View Full Version : Car AMP7, AMP15 and Truepath
Hi,
I have connected up a circuit that creates 2x40Vdc, 1x10Vdc and 1x5Vdc out of 10-15Vdc.
AND IT WORKS!
And it can deliver a LOT of current...
Have been bench testing it on AMP7 at full power and there's fine audio and stable rail voltage...
Got this chunk of PCB and a core for the toroidal transformer from a friend. Put all the other parts together myself...
It uses a 3525 switcher at 45Khz...
Now it's just a matter of boxing it up and I've got a BRUTAL car amplifier![}:)]
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000384.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000385.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000386.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000387.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000388.JPG
------X-max. can be several meters on any driver, too bad it can be done only once...------
wow... how much current does it draw from a car battery ??
Does anyone know how much current can a normal car battery handle ?
V-bro, you make me sick..... [:p]
***It's so easy, everyone should be doing it***
It's sick indeed isn't it?! :D
It draws 1A on average, 250mA at idle and i can see peaks of 3,5A but the meters in my lab supply are rather slow...
quote:Originally posted by mikechw
wow... how much current does it draw from a car battery ??
Does anyone know how much current can a normal car battery handle ?
A car battery delivers several hundreds of amperes on starting up your car...
------X-max. can be several meters on any driver, too bad it can be done only once...------
Nice,
what kind of case did you have in mind?
I may hook up a Truepath after all. Just because it has a blue PCB just like the converter ;)
And it's more compact....
------X-max. can be several meters on any driver, too bad it can be done only once...------
Such a power supply should Jan have as an kit option, it`s not many places that sells smps kits for cars.. i only know about coldamps version, but that is pricy! But maybe it`s hard to get working for the hobbyist?? :D
maybe not hard to get working, but possibly very dangerous!
here's a design that uses the same chip as v-bro's board above:
http://sound.westhost.com/project89.htm
Indeed such a kit would be nice and not half as dangerous as a mains SMPS, but the transformer is a hard to source part. The UC3525 can be adjusted in frequency and the transformer needs to suit the frequency or vice versa. It's not rocket science to wind your own on a toroidal core just like this one, but it's not rocket science to build a working AMP6 either and still a few people manage to mess it up...
quote:Originally posted by krilli
Nice,
what kind of case did you have in mind?
A die cast box like I always (almost always) use...
I hooked up a Truepath, the AMP7 didn't fit in the designated box and the blue PCB's just look cool together. (not that anyone cares because the box is gonna be closed anyway...)
Not completely finished yet, but working VERY well. Here it is:
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000389.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000390.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000391.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000392.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000393.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000394.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000395.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000396.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000397.JPG
------X-max. can be several meters on any driver, too bad it can be done only once...------
dang. the converter looked like it was made for the case! still thinking of how I'm gonna proceed with mine. I recently got a bandsaw so cutting heatsinks and aluminum railing for cases should be easier. :D
I made it fit snug by soldering the fets and rectifiers on again. I was lucky this was possible at all...real lucky...:)
You do have all the electronics up and running haven't you?
------X-max. can be several meters on any driver, too bad it can be done only once...------
offtopic: well, amp9B is still blown (wasn't able to buy another chip yet) amp1 module is tested and working. only a new SMPS is not yet built.
If anyone wants to get this sort of a power supply to hook up a big amp look for certain second hand big car amplifiers from the stone age. This particular power supply appeared to come from a delorean DL-270 power amp.
I saw a DL-290 for sale for 22Eur!
http://www.kapaza.be/Audio/Versterkers/14873171/De_Lorean_DL_290.html
I just bought a Delorean DL-600 which has a dual transformer power supply inside, paid just 30Eur!!
Now THAT is nice for an AMP7!
------X-max. can be several meters on any driver, too bad it can be done only once...------
If you only need to power your amp from a car battery for one day and dont need it to be constant then you should better use a 12V to 230V(or whatever your mains-voltage is) converter you can buy at electronic stores and then power your amp with your normal mains-supply. They are cheap and small right now and not nearly as dangerous as building one yourself.
Not that anybody reading this here thinks, he necessarily needs to build all this just to power his amp from a car battery!
Sure Kuddeldu, but that's not half as efficient and still takes connecting up a mains supply. So it involves dangerous voltages, costs MUCH more because it's not only the converter, but also the mains supply AND it's not much easier than connecting up this supply...AND it is MUCH less compact, a mains supply needs much larger caps and a big transformer or SMPS and on top you get the converter which has to be quite beefy as well...
Keep in mind (as can be read in the Rod Elliot article) that from a 4cm dia. 1 square cm core transformer you can already create a 300W supply!!
I have gone further and these are new projects coming up:
AMP7 on a dual converter and AMP15 on a similar converter as above...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000412.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000413.JPG
The dual supply...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000409.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000410.JPG
AMP7 and the dual supply together...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000407.JPG
The other single supply in original state:
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000399.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000398.JPG
In the modded state with all new caps and 18 secondary windings instead of 12, this makes the output voltage about 2x40Vdc instead of the 2x28Vdc it had....plus the windings are litz wire now...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000404.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000402.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000403.JPG
The single supply and AMP15 together...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000401.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000405.JPG
I have installed two 10000uF 50V caps on the AMP15 to make it very low profile. On top -like I said above- the amp doesn't need as much capacity with a fast switching supply as it would need with a mains supply...
------X-max. can be several meters on any driver, too bad it can be done only once...------
V-bro,
Of course your built is much more efficient and smaller than a converter plus mains supply and perfect as a caramplifier!
But if you just want to take your already assembled and working amp on a trip for a day then its probably a better choice to use a converter instead of building another supply! A friend of mine connected one to a single car battery and powered a 300W amplifier with it. We were able to listen to music at full volume the whole day! And it was pretty cheap and small: 25 for the converter (at about 15x6x5cm)!
No offence for your work! Just wanted to mention it as a possible alternative.
Ok, I got the idea... Didn't mean to attack upon you personally, just stress that such a thing is not a good permanent solution...
------X-max. can be several meters on any driver, too bad it can be done only once...------
quote:Originally posted by djQUAN
offtopic: well, amp9B is still blown (wasn't able to buy another chip yet) amp1 module is tested and working. only a new SMPS is not yet built.
What rev. board of AMP9B do you have? 1.1 seems to blow chips, 1.11 is corrected...
------X-max. can be several meters on any driver, too bad it can be done only once...------
quote:Originally posted by Kuddeldu
V-bro,
Of course your built is much more efficient and smaller than a converter plus mains supply and perfect as a caramplifier!
But if you just want to take your already assembled and working amp on a trip for a day then its probably a better choice to use a converter instead of building another supply! A friend of mine connected one to a single car battery and powered a 300W amplifier with it. We were able to listen to music at full volume the whole day! And it was pretty cheap and small: 25 for the converter (at about 15x6x5cm)!
No offence for your work! Just wanted to mention it as a possible alternative.
Sorry, I have to agree with V-bro.
As a one day, temporary use, that will work, but as a permanent install it is not really a viable solution.
Otherwise car audio amp manufacturers would be using these inverters in their amps. Inverting 12VDC to 120V/60hz or 230V/50hz and then transforming it back down to DC adds cost, complexity, weight and heat, compared to a basic high frequency dc-dc convertor.
My Tacoma truck comes from the factory with a 400W invertor, but I would not consider using this to power an amplifier.
***It's so easy, everyone should be doing it***
Whoa you've got one of those big Toyota pickups?! That must drink up quite a lot of juice doesn't it?
Well it must have a big enough alternator to power some serious amps with! :D
------X-max. can be several meters on any driver, too bad it can be done only once...------
Sadly, I still am running the stock sound system.
I'm into SQL not SPL, so the AMP9 should be fine with some upgraded speakers.
....although it would be nice to have increased head-room with a couple AMP11's or an AMP7 [8D]
http://www.xr-underground.com/forum/member.php?u=389
***It's so easy, everyone should be doing it***
quote:Originally posted by V-bro
quote:Originally posted by djQUAN
offtopic: well, amp9B is still blown (wasn't able to buy another chip yet) amp1 module is tested and working. only a new SMPS is not yet built.
What rev. board of AMP9B do you have? 1.1 seems to blow chips, 1.11 is corrected...
------X-max. can be several meters on any driver, too bad it can be done only once...------
it's rev 1.11
my clumsy accident was touching the mute pin to the on/off pin.[B)]
quote:Originally posted by djQUAN
quote:Originally posted by V-bro
quote:Originally posted by djQUAN
offtopic: well, amp9B is still blown (wasn't able to buy another chip yet) amp1 module is tested and working. only a new SMPS is not yet built.
What rev. board of AMP9B do you have? 1.1 seems to blow chips, 1.11 is corrected...
------X-max. can be several meters on any driver, too bad it can be done only once...------
it's rev 1.11
my clumsy accident was touching the mute pin to the on/off pin.[B)]
Gosh what a waste... These chips are expensive!
------X-max. can be several meters on any driver, too bad it can be done only once...------
quote:Originally posted by Scratchy
Sadly, I still am running the stock sound system.
I'm into SQL not SPL, so the AMP9 should be fine with some upgraded speakers.
....although it would be nice to have increased head-room with a couple AMP11's or an AMP7 [8D]
http://www.xr-underground.com/forum/member.php?u=389
***It's so easy, everyone should be doing it***
Been listening to the Truepath in my car and it is simply outstanding how great it sounds, I'm also not into SPL, only SQL!http://www.snapdrive.net/files/361770/Posting%20photos/rockonsmilie.gif
:D
I had an AMP32 in there for a year and it wasn't half bad, but after this swap I can only conclude the 32 is a nice toy, nothing more....
------X-max. can be several meters on any driver, too bad it can be done only once...------
not only expensive, but also a diminishing resource!!! I have to buy one before supply runs out.
I have been using amp2 in my car for around 4 years I think. currently driving midbasses in the doors. a class AB amp drives the tweets. will replace that one with amp1. :D
You also had an AMP8 right? Or did you blow that one up? I seem to vaguely remember...
------X-max. can be several meters on any driver, too bad it can be done only once...------
yep it's still in running condition. although I never finished its SMPS so it's been sitting on the shelf collecting dust. might resurrect it again someday. :)
What a waste DJ...[8)]
I've found just the prefect casing for my car AMP15! It's also from Modushop.biz...
I'm gonna put the boards in there stacked, one on the bottom, the other on the top...
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000423.JPG
------X-max. can be several meters on any driver, too bad it can be done only once...------
What do you think DJ? I've got 2x3 680uF 100V caps on the converter, two 10000uF 50V on the AMP15 and four 330uF 100V close-up- caps on the AMP15. Would that be too much capacity for this converter?
How would one calculate this?
------X-max. can be several meters on any driver, too bad it can be done only once...------
it should be just right. not sure how the SMPS handles the inrush current. it should have a slow soft start when you turn it on. if not, it would draw a huge current at power up.
Thanks! I tested the supply just with the same caps yesterday and the current draw wasn't too bad, the softstart pin is indeed in use in this supply...
------X-max. can be several meters on any driver, too bad it can be done only once...------
Dang! That AMP15 sounds freaking good!!! No sharpness, tremendous power and ultra smoooooth!
Just simply amazing for such a "small" amp...
Here's how it looks now:
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000433.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000434.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000432.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/P1000431.JPG
http://www.snapdrive.net/files/361770/AMP7/CAR%20AMP7/kP1000423.JPG
It may not be incredibly beautiful, but it does sound that way. And it IS nicely compact and robust.
------X-max. can be several meters on any driver, too bad it can be done only once...------
Been playing for two hours now (as a car amp, this amp's been long term tested on the lab supply before) and it is running VERY cool, the unit is not warmer than my hands...
I have 4 ohm speakers connected and the 12V converter is outputting around +/-40Vdc.
------X-max. can be several meters on any driver, too bad it can be done only once...------
That's a great size and case for an automotive amp V-bro.
I'm wondering why you blocked off the vent slots on the top plate?
Even if it does run cool, it's always good to have some airflow [?]
***It's so easy, everyone should be doing it***
Thanks Scratchy! [8D]
It's not entirely blocked by the way, the top lid is lifted by a plate (4mm thick aluminium) that cools the AMP15 (which is mounted upside down) leaving large slots under the front and back and a little on the sides of the top lid...
Additionally there are still slots in the bottom.
Besides I've been putting 41hz amps in completely sealed enclosures that never failed me either...
After some torture tests I'm convinced it is running cool enough the way it is.
------X-max. can be several meters on any driver, too bad it can be done only once...------
I have placed both amps in my car and must say the sound is absolutely breathtaking! It is both SQ AND SPL, although the SPL is probably not up to the level to compete in those decibel contests. But then again that would mean I'd have to get some extra glass insurance...;)
I've tried AMP32 and AMP9 only so far. AMP9 is a great little amp as well, but at highest output it could benefit from more than 12V supply voltage...
------X-max. can be several meters on any driver, too bad it can be done only once...------
The amps have been playing in the tremendous heat of the south of France in midsummer for over a month. Outside temperatures were almost 40 degrees Celsius. There have not been any overheating problems whatsoever.
Just beautiful sound...
------X-max. can be several meters on any driver, too bad it can be done only once...------
I saw another Delorean for sale:
http://link.marktplaats.nl/319669242
For sale in Holland... This is quite the ultimate converter for a medium power Truepath, AMP15 or AMP7. For those who can't wait for my converter design...
For those who can't wait for my converter design...
good work v-bro, i've been following many of your posts with interest.
how are you doing with the converter design? i've seen on other threads that you got some pcbs recently ( april ? )and were testing, did they work?
i ask becasue i'm trying to work out how i'd get one of the higher powered amps running off of a 30 Ah 24v LiFePO4 battery. ( the 2 speakers i'm going to use are 8 ohm so the amp9 will only go to 50w peak as i understand it... and i'd prefer more :-) !!! )
cheers,
simon
Hi Simon,
I'm glad someone asks about it! I thought I would get more responses about it actually. :confused:
It's going great, the PCB's works perfectly and I've found fets that perform like a dream. The idle current with the present transformer cores is down to 40-50mA, which is quite spectacular. I'm more or less done with the design. A student at work, who we all have to thank for his great effort in getting the design to actually lift off has built an AMP2 with it and it rocks big time!! It's super small!! (just 125x230x40mm!!)
I have thrown the design in Jan's lap to re-design it to his wishes. He wants to use as many parts on it as possible that he already stocks and he also wants to have it in his design software to be able to make newer rev. boards with more ease. Also, we have made an SMD modulator board (tiny card to stick on top of the main board) and Jan probably wants a through-hole version as well...
I can order more boards on request, but at low quantity the prices are less attractive of course.. I paid about 45Eur. for the main board and modulator board together. This was at a quantity of six each. The tiny modulator board is almost the same price as the large main board....
For those who want SERIOUS power from a 12V supply voltage THERE IS NO OTHER WAY then to use this type of a converter. I think not many newbies know that. EVERY car audio amplifier with more than 25 real watts per channel uses this type of a converter inside!!
cool!
so that means if i want to get one i either wait for Jan to bring it out in x months ( any idea what his average time to do something like that is ? )
or ask you nicely to get some more of your boards ( was it 45 euro for 6 pairs of boards or 45 euro for one pair ? ) and i send you some money and try and work it out myself ( hopefully with a list of parts from you or i'll have no chance !. )
NOTE - i haven't had much smd experience but have the kit and a steady hand so should be ok. however my knowledge of electronics stretches only up to folloing plans and lists !
my current plan is to make a fairly loud soundsytem to go on the back of a LWB bike (http://www.rideyourbike.com/bigdummy.html).
one of these dr250 (http://billfitzmaurice.net/DR250.html) or even more stupidly two if they don't put the centre of gravity too high on the bike. ( but i digress ..... )
The battery will likely be 24v as i said before so would your circuit be adaptable to convert from a 24v input instead of 12v?
i'm hoping to use a amp10basic or amp15 because the drivers i need for the cab design don't come in 4ohm, only 8ohm so the amp9's big current capabilities will be a bit wasted if i understand things correctly.
cheers for any advice / help.
and cheers for all the advice help and inspiring work you've already put into the forum. :-)
The circuit can certainly be adapted to 24V input, no problem. If I remember correctly the SG3525 can handle up to 35Vdc input voltage. That's the main part, the rest is just caps, resistors and an opamp. The transformer winding ratio determines the output voltage, so with 24V input you need just a few secondary windings more than the primary to get a decent voltage for the AMP10-B.
The AMP15 is certainly a very good choice as well, although you might just as well take a Truepath or AMP7, they have the same output voltage on an 8 ohm speaker, but can deliver more current when needed.
Don't overlook the AMP11 either! Or better the AMP11-HV, or I could even guide you to get an AMP4-HV up and running, which is good for 160W/ch on 8 ohm speakers!
The PCB's price is per single pair I'm afraid, but the rest of the parts don't cost an arm and a leg. I've already put in hundreds of euro's in the development, but I can tell you which parts to get now, without too much need for experimentation. I could even get you a bunch of parts in a bag that'll fit perfect and work well for sure.
Winding the transformer is relatively easy, there are just a few windings needed on such a high frequency....
Nice project!:)
Double cool !! :cool:
Thanks V-bro! i'm pretty excited now as that means after many days of going round in circles trying to work out what power supply/amp/driver/cab combo to go for i think i know now - which means i get to get building soon! ;)
So after looking at the amps you suggest, it seems to me that i should go for the am4 HV or a truepath.
the drivers i'll be using are rated at 250w so maybe i should err on the side of caution ( and battery life ) to start with and build the amp4 HV and see how that goes.
[:confused:or should i 'go big' and get a truepath going and never turn it up full! ( or give it 50v not 60v to keep the watts down ?) - then if i ever add more speakers in parallel i can adjust your voltage converter circuit down further to 45 v and it'll still be able to deliver 2x300w at 4ohm.]
hmmm decisions decisions. :) i suppose cost comes into it too, the amp4 being around 50euro and the truepath 97euro plus power supply board (67euro ) and voltage regulator kit ( 27euro ) = 191...
is it correct to assume the cost of the amp4 hv will be roughly similar to the standard amp4. if so i think i'll settle for that - if you can point me in the right direction of how to do the upgrade!.
and thanks for the offer of the voltage converter board pair and parts goodie bag! that's exactly what i'd need to give me a fighting chance. :).. how do we orgainse swapping money for bits and pieces?
and do i need to get the standard amp4 from 41hz and you tell me how to convert it to HV or is it more involved?
i'd appologise for all the questions but i know there will be more - so i can only offer to swap them for enthusiastic thanks and photos of the build as i go along ;)
I'm quite sure you'll be splendidly happy with the AMP4-HV and it is indeed less costly, easier to connect, more compact and really really powerful.
The good thing is that my voltage converter can be configured single output double current, so it'll be a very good match for this amp!
I made a -HV BOM (bill of materials) in the AMP4-HV thread I made. If you have trouble sourcing components and want to have the -HV upgrade kit I can also put it together and send it to you. You can start with a normal AMP4 and a separate STA517B chip....
Then the calculation you made for Truepath isn't quite correct, you only need the PSU1-VR kit. The PSU1-PS kit isn't necessary because this converter is an SMPS and doesn't need all those large caps. The PSU1-SS kit is also not necessary because there is no large transformer to start up...
Today I have made a parts list for the converter, so I have a total price in mind now, roughly...
I have also considered ordering a larger batch of PCB's to get a better price a piece. A 20 pieces batch already lowers the price considerably.
Perhaps this is a good chance for other guys to show interest? If Jan doesn't mind.... I think we can bring down the kit price to just over 100 euro's....Perhaps even less.... Right now this still is about 140....that's without profit...That is with the transformer core, PCB's and all resistors, caps, the fets, rectifiers, jumpers, PWM modulator parts, screw terminals, enamelled copper wire, the opamp and thermal sensor....
I indeed love to see pics along the way! :) I'm also quite interested in other persons testing the converter design....
Excellent!! I'll give it a go then! :D
To get things clear - (for myself and for anyone else reading the thread )
From 41Hz I'll order the:
AMP4
STA517B chip
And ask you for the:
AMP4 HV upgrade kit.
And your voltage converter kit ( boards and parts ) so i can run it off a 24v LiFePO4 supply .
is there anything else i'll need?
I can wait for a bit if you want to see if others are interested - for ordering more boards in bulk, as i've still got to build the speaker cabs yet, (and they don't look that straightforward either), but tell me how / where to send money whenever you're ready. paypal?
I'm looking forward to a future bike sound system that will beat the cars! ;)
Hah! You WILL beat cars with ease! I've already beat cars with my 'macaroni' bike sound system with AMP32!
Well anyway, I indeed have a Paypal address, no problem.
I'll put the -HV upgrade kit and converter kit together as soon as possible. The first rev. converter board worked perfectly well right away, so the next batch won't be much improved anyway. We'll sort out the price later on then, when there will be a group buy the price will go down, if not we'll stay with ordering just six more boards...
Hey V-bro,
I'll buy a 12V SMPS converter if all the parts are included in the kit as you mentioned, as well as the PCB's.
I think it best we get 12 people to commit to one of these kits in a group buy, before you order 20 more pairs of PCB's.
I can start a new GB thread for you if you like?
Hey V-bro,
I'll buy a 12V SMPS converter if all the parts are included in the kit as you mentioned, as well as the PCB's.
I think it best we get 12 people to commit to one of these kits in a group buy, before you order 20 more pairs of PCB's.
I can start a new GB thread for you if you like?
By all means start another thread! Thanks! Only thing I would like to have clear is that Jan is not planning on selling this kit for the coming months. If he is, I think we all rather order it from 41hz, if not I think I speak on behalf of many people that we don't want to wait that long either... I don't want to shoot under Jan's clay pigeons of course. But I don't think he'll have to worry about the few here on the forum getting this on the road, as soon as he releases such a kit it'll sell big numbers anyway... Jan should probably be glad we're doing further testing on the design...
..Jan is not planning on selling this kit for the coming months. If he is, I think we all rather order it from 41hz, if ... Jan should probably be glad we're doing further testing on the design...
Well I'd like to be in the loop and get started with this as soon as possible.
Last months: Had some vaccation, had some flue, did some web updates. Now it's time for technical development again! The fun stuff!
i agree with your ideas - anyway it'll increase sales from me for starters, cause i'll be buying a amp4 and chip already instead of using trhe amp9 kit i have already got....
scratchy - where is the new GB thread?
We would be glad to have you in the loop Jan, because then the price and quality will be at the best level. You can buy the parts and PCB's in bulk, which is eventually cheaper even for the end user. Today I have asked what different quantity batches cost and the total price difference between 20pcs or 100pcs is just plain minimal!! But 100 pieces is too much for a group buy, so there you go.
I would give this project a very high priority Jan! Before someone on the other side of the globe walks away with it!
I just want to say that I will DEFINITELY be buying a few of those converter kits; I am completely broke at the moment, but I'll buy as soon as I have any spare cash. Just to put the interest out there.
Today the student who has chosen this converter as his graduation project graduated on it, so big hurray for him!:D
In his presentation he chose to compare this amplifier to a mains operated class A amplifier, namely a Passlabs X150.5 This amplifier has recently been completely refurbished and brought back into specs.
The difference in all aspects was striking!!:eek:
We started with a DVD listening session of Hotel California by the Eagles on the AMP2 with 12V->2x50V up converter. It sounded superb, you could hear the compression applied on the acoustic solo guitars, there is a sort of synthesizer sound in the background at a point that moves from bottom left all the way to top right in the 'image' and you could literally pick it out. All secret back ground information unveiled itself so incredibly well, and paired with a neutrality insurpassed! I'm quite stunned by the AMP2 actually. I thought this amp would be a nice cheaper alternative for a goal where superb audio is not of the utmost importance, namely car audio, but I've been proven totally wrong in this assumption... Of course I've heard the differences before, but it is always more striking when you least expect it...
Then the Passlabs X150.5 As soon as we connected (it had been on for hours warming it up though!) it and unmuted it it was producing terrible hum in the audio! Then I disconnected the video cable towards the LCD screen, different hum, still there... Then I disconnected the earth from the source, gone! I CAN'T BELIEVE a €5000 amplifier doen't have it's grounding plan made properly, or doesn't feature a ground lift option!! Not a good start of course... The CAR-AMP2 had no problems like this at all! Even though we used an earthed 13,8V 20A power supply as we didn't feel like burning holes in the carpet with the acid from a car battery...
I thought this Passlabs amp would sound much the same, or at least better than a 12V operated amplifier! Well I've got news for you, it didn't! And this is not only my opinion, but the opinion of a 20 head crowd. It was a very clear difference, not leaving any speck of doubt. We have had a session in an audio suite in the company where I work. Excellent Westlake speakers, great Studer CD player as source and a Philips DVD/SACD player.
The Passlabs sounded much more coloured, much less lively and articulated, presented a far less wide and deep image of sound as if the sound was just stuck into the speakers. With the AMP2 operating on the converter everything opened up so nicely, just shocking.
Even up to PA SPL level the AMP2 was going strong. The 13,8V PS was redhot afterwards, but the converter and AMP2 we're just barely warm to the touch... The converter has proven itself to be a really stable, silent and well designed power supply. And there is still much room for improvement by changing to a different bunch of fets and a different transformer. Our power tests have proven this supply to be good for just under 500W continuous power and then it collapsed, with the other fets and transformer we are planning to use in the next assembly we expect to go for several hundred watts more... And we don't just guess, we know from the experience we've gained so far....:cool:
I have a traditional car amplifier here which is 44x26x5cm large and less powerful, super heavy and running hot, this CAR-AMP2 is just 23x12x4cm!!!
Congratulations on a job well done :)
That certainly sounds like a well designed & built SMPS.
I think if these are sold as DIY kits, there is a good market for them, along with the AMP2 or AMP7 for automotive use.
Especially if these are showcased in an automotive SQL competition and word gets out about the sound qualities you have mentioned.
This is really good to hear that someone has designed something like this (i have not found any kits like this for sale elsewhere).
The only thing missing is a good DAC kit now!
Well I'd like to be in the loop and get started with this as soon as possible.
Last months: Had some vaccation, had some flue, did some web updates. Now it's time for technical development again! The fun stuff!
Sorry, but I somehow missed this part of the thread.
If Jan can develop this into a kit in the next 3 months or so, then I think we should wait for his Kit.
Sorry, but I somehow missed this part of the thread.
If Jan can develop this into a kit in the next 3 months or so, then I think we should wait for his Kit.
except for me cause i can't wait that long !
i'd totally like a kit as i assume it will all be a bit easier to do but my speakers are coming along and i'm going to want a sooooped up amp that can run on 12/24 v sooner than that...
if it's ok, and that sort of length of time is about right for the kit, can i still go ahead with your kind offer v-bro?
don't worry about sales, once my system is working i'm sure i'll be pointing many people in the direction of 41hz for the official kit when it's out ! :)
Also, I guess we can move to 'part 2': mains smps 120/240Vac/300-600W > 2x 20-60Vdc (set by windings on toroid), so we can have a very compact smps to power the amps from mains too. Perfect complement ?
It would be great, but I'm very scared of mains-voltage SMPS'es. I'd have to be convinced that it was a reasonable DIY project.
Some files are still not final and problematic. Like the Gerber files, sadly no PCB design program allows to import gerber files to edit. Logical because there are differences in footprints, style, options etc. etc. in each design program. This converter was done in Eagle and Jan uses something different. Leaves only the option for Jan to copy the design by re-designing it by hand. This is necessary too to be able to make small adjustments and new rev. boards.
Then the BOM, this is usable only for my design, Jan has to make a new BOM for his. But it can be greatly inspired on mine...
Then the schematic, well it's a pretty simple one, shouldn't be too challenging and the one I've drawn up is very clear and clean.
AI still needs to be written, I have a really large Dutch document of the design process, but nothing usable as AI.... But the transformer part is the most challenging and needs most explanations in order to get the right voltage and lowest noise. It's not much harder than winding the inductors for a Truepath for instance, but I've seen a few that have been done pretty bad, especially the (lack of) enamel removal...
Mains, nah... too dangerous, too many fine Chinese products that are so cheap that there's no way it can compete business wise...
bump to this thread, is there any news of a kit for this yet?
Working on it 24/7 yes.... A medium size unit is going on the test bench soon.... Tests will have to be performed and if all is positive we might see a small size SMPS soon!
I had one of V-bros boards up and running but did not get the regulation I wanted, even if it was a non-feedback / non-regulated mode. Voltage simply drooped too mych under load compared to idle. I have some new boards arriving this week. The design is similar to V-bros but not identical. It has a sub-board for the IC and the main board can be set up in variouse ways. I will post when there is progress...
But did you actually try with all six fets? And how did the transformer look then? I had pretty stable voltage on mine...
thanks ofr the update! guess i'm too impatient :-) !
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