View Full Version : Before start the assembling of Truepath
Hello !
I am ready to start the assembly of the Truepath(Finally I have time!). I can see a LOT of posts about the differents configurations, improvements, update assembly instructions, etc, etc, etc.
I have the document assembly from Thomaselliot, and the 41hz doc first draft.....I should know anything more for not to make a bad assembly, because bad or missing information?..Thanks a lot.:)
quote:Originally posted by abelma
Hello !
I am ready to start the assembly of the Truepath(Finally I have time!). I can see a LOT of posts about the different configurations, improvements, update assembly instructions, etc, etc, etc.
I have the document assembly from Thomaselliot, and the 41hz doc first draft.....I should know anything more for not to make a bad assembly, because bad or missing information?..Thanks a lot.:)
It's pretty straight forward. Start with the lowest comps and mount the highest last.
If you have the equipment, measure the resistors and capacitors before mounting, just to be sure it's right value.
Be thorough. Use a hot soldering iron. Don't use too much solder. Check the solder-joints. (You probably need a magnifying glass, I sure do [:I]). Check for shorts now and then.
Good luck ;)
/B
PS. You know where to find us
Thanks!
I have all those tools, but not a capacitor tester (Looking for).
My configuration will be with a switch power source with an output fixed voltage of +-60. Also, this power source has a +-12 V that I will use for VN10 and V5. I think if connected the PSU1-VR with input of DC 12V, I should not have any problem to have DC 10V and DC 5V after the PSU1-VR...right ?
The input source will be a CD player with volume control inside, so Ill use the Rin= 47K and Rfdbk=22K. But for later, I am thinking to use an active preamplifier kit, that I could change the level output to match the level entry of the amplifier. If not, I dont see too much problem changing Rin and Rdfbk.
After reading the posts, I will use a temperature of 450 C in my iron solder.
Ready to start the assembly, and I'll keep you posted. Thank you
audiophool
25-Mar-08, 12:56
Hi abelma,
If you haven't already done so, please take a look at http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1252&whichpage=9
and
http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1252&whichpage=10
The notes about organizing and soldering the SMT components and preparing the litz coils may be useful. One of these days, I'll PDF all of my assembly notes into a single contiguous PDF!
thomaseliot
25-Mar-08, 13:30
quote:Originally posted by abelma
...Also, this power source has a +-12 V that I will use for VN10 and V5. I think if connected the PSU1-VR with input of DC 12V, I should not have any problem to have DC 10V and DC 5V after the PSU1-VR...right ?
Remember that VN10 and 5V cannot share the same ground. 5V ground is referenced to 0V and power ground (PGND) while VN10 is referenced to VNN (your -60V +10V = -50V). So you need two positive 12V (with no ground in common) out of your power source.
I'd just use a small transformer with two secondaries to power the PSU1-VR. :)
Hi Abelma, there are pretty affordable capacitor meters at conrad.nl...
http://www.conrad.nl/goto/?product=122211
<img src="http://images.conrad.com/m/1000_1999/1200/1220/1222/122211_BB_00_FB.EPS.jpg">
------X-max. can be several meters on any driver, too bad it can be done only once...------
Thank You guys !
To ThomasElliot: This power source has like output +- 60 V (-60,0,+60), and +-12 V (-12,0,+12). The two ouput voltages are isolated to each other.
I was thinking to use for VN10 the -12,0 output. So, I should have a voltage potential of Dc12V, with the 0 pin like +12V.
In other hand, the same for V5, but the 0 pin should be the -12V.
I hope I am clear. In this case VN10 and V5 do not share common ground ?..
Hey Vbro, this instrument should work very well also for measure the coils ? The range seems ok.
C 0 tot 2 nF - 200 F 2% + 3 digits
L 0 - 2 mH - 2 H 3% + 3 digits
thomaseliot
25-Mar-08, 20:25
quote:Originally posted by abelma
I was thinking to use for VN10 the -12,0 output. So, I should have a voltage potential of Dc12V, with the 0 pin like +12V.
In other hand, the same for V5, but the 0 pin should be the -12V.
I hope I am clear. In this case VN10 and V5 do not share common ground ?..
I'd look carefully at your SMPS datasheet and schematics. Is it Coldamp SPS30?
I don't understand so much of SMPS, but in my opinion all +/-60V, +/-12V supplies and their chassis, share the same 0V potential connected to the wall outlet ground.
it is the Coldamp SPS80, 800 watts !
The technical specifications says that the two supplies are complete isolated each other.
The wall outlet ground is not connected to the output supplies of +-12 and +-60.
Eh...no uH values will just fall out of range for this one, or well it just barely shows it, but not very precise....
But they do have other models with higher precision...ofcourse not that cheap....
------X-max. can be several meters on any driver, too bad it can be done only once...------
thomaseliot
25-Mar-08, 23:22
Reading SPS80 datasheet it is clear that SMPS ground is not connected to mains ground and +/-12V supply is insulated from main supply (maybe there is another dedicated buck converter). This is not enough. +12V PS and -12V PS must not share the same 0V potential: this is not clear reading datasheet and I would ask for it to manufacturer.
Bear in mind that from the +12V 0V -12V supply you must have 4 voltages at PSU1-VR output (when connected to Truepath) and not only three (as is the case if you have only one 0V): +5V, 0V (Truepath AGND), -50V (10V more positive than VNN), -60V (negative side of VN10 connected to VNN). If you have not two 0V floating, when you connect VNN (-60V) to the regulator board you will get -55V as AGND, because the negative side of +5V supply is connected to the negative side of VN10 via the common ground of SPS80.
Vincent, what uH values are you referring to?
Ok Vbro....so, looking for a multimeter with the possibility to measure the coils too...anybody some recommendation?...
ok Thomas,
"If you have not two 0V floating, when you connect VNN (-60V) to the regulator board you will get -55V as AGND, because the negative side of +5V supply is connected to the negative side of VN10 via the common ground of SPS80."
Sorry for my "amateur" side of this..=)....but in the way I can see my (Wrong?) idea is that +5V and +10V do not share the same ground (?). The negative side of +5V its the -12 (Of -12,0,+12), and the negative side of +10V its the "0" ( Of -12,0,+12).....in this case they do not share the grounds, but, I can see also that there is not a complete separation between +5V and +10V. I dont have the tech skills to know if I am wrong or right, but, I am sure that you do better than me :D
http://www.conrad.nl/goto/?product=120982
http://www.conrad.nl/goto/?product=100971
http://www.conrad.nl/goto/?product=121248
http://www.conrad.nl/goto/?product=121307
And if you really wanna go pro:
http://www.conrad.nl/goto/?product=120507
------X-max. can be several meters on any driver, too bad it can be done only once...------
And I think the +/-12V of SPS80 is not suitable. You need two entirely separate 12V supplies. If you do what you propose than you will short either of the 12V outputs to the ground of either the 5V or VN10 board of PS1VR....
This will not happen on the PS1-VR board, but as soon as you connect it to Truepath there WILL be short circuits!
A small single extra supply would work, than you just use a single 12V of the SPS80 (and perhaps dummyload the other)....
------X-max. can be several meters on any driver, too bad it can be done only once...------
thanks for the links...the 4080 look pretty good
In case that my idea is not suitable...so...I should use that extra +-12 V for a preamplifier or other accesories.
Looking the Truepath assembly instructions, it says that for use with 4 ohms loads and voltage higher than +-50 V (My case), it is necessary to update some components. The issue here is that it not says "wich" components to change, and their values...It could be the resistors for the current limiting ?
quote:Originally posted by abelma
thanks for the links...the 4080 look pretty good
GULP!! 980 euros for an hobbist multimeter it's way too much i think (but if you can afford, go for it), i would buy it only for a research center or a very specialized repairer. For me, as an hobbist repairer of radio/tv sets, i've spent 60 euro for the multimeter and it works well enough...another 25 for the (Chinese) LC meter.
Try to search on ebay, there is a lot of stuff.
Bye
Gianluca
Ciao Gianluca,
The 4080 Voltcraft cost 135 euros !.
A few months ago,Ive tried the Velleman LCR meter (60 euros), and it didnt measure very well the coils of my amp10.
Can you please tell the chinese that it works? Thanks
quote:Originally posted by abelma
Ciao Gianluca,
The 4080 Voltcraft cost 135 euros !.
A few months ago,Ive tried the Velleman LCR meter (60 euros), and it didnt measure very well the coils of my amp10.
Can you please tell the chinese that it works? Thanks
Looked at the wrong one [:I]
I can tell if it works when it arrives :D I hope that it works well.... Judging by the specifications it has a +-2% precision for inductance below 200mH, so, if it's true, i think it's enough for my hobby projects. Actually the user didn't have another in auction, this is the link of the one i bought:
http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&rd=1&item=150226409878&ssPageName=STRK:MEWN:IT&ih=005
I'll let you know when arrives.
Ciao.
Gianluca
thomaseliot
26-Mar-08, 14:01
quote:Originally posted by abelma
Sorry for my "amateur" side of this..=)....but in the way I can see my (Wrong?) idea is that +5V and +10V do not share the same ground (?). The negative side of +5V its the -12 (Of -12,0,+12), and the negative side of +10V its the "0" ( Of -12,0,+12).....in this case they do not share the grounds, but, I can see also that there is not a complete separation between +5V and +10V. I dont have the tech skills to know if I am wrong or right, but, I am sure that you do better than me :D
When you connect +12 0 -12 to PSU1-VR in the way you said, I agree, you get +5V, 0V and +10V, 0V when you measure with a multimeter at the PSU1-VR outputs.
Now you have to produce VN10 to connect to Truepath: it must be 10V more positive than VNN, in your case -50V. How do you produce it? You connect VNN to the negative side of the +10V power supply, so the positive side of the +10V power supply becomes -50V (+10V - 60V = -50V).
After that, all circuits connected to the negative side of the +10V PS will lower their potential by -60V. In your case, the 0V in the +12V, 0V, -12V, and the positive side of the +5V PS: 0V and -12V are shorted and, worse, that 0V is the same 0V (I suspect) of +60V 0V -60V PS, so you shorted -60V to ground too.
My hint is a cheap small 30VA toroidal transformer with 2 secondaries: it will supply much cleaner +5V to Truepath.
Another option, if space is an issue, is to use the new PS2 DC-DC regulator to get VN10 directly from VNN and you your aux supply for +5V.
looking closer the sps80, the auxiliary output +-12V is totally isolated from the +-60V supply, also, the tech specs says the same. The auxiliary output has two regulators Ic, and it is not a smps output.
Anyway, my idea was to not add more that one transformer, and it will be the case, because I could use the +-12V for supply a preamp.
Thats a good idea Thomaselliot, with the PS2 !..So, in this way, no transformer for the amplifier stage. Then, for the active preamp and dedicated transformer.
Looking the Truepath assembly instructions, it says that for use with 4 ohms loads and voltage higher than +-50 V (My case), it is necessary to update some components. The issue here is that it not says "wich" components to change, and their values...It could be the resistors for the current limiting ?
Ofcourse! PS2, I should have advised this before as I've just built one myself![:I]
It works like a charm, very efficient circuit!
That 4080 meter seems like a good bet, I was contemplating on buying one myself, unless there's a good chinese alternative...[:p]
------X-max. can be several meters on any driver, too bad it can be done only once...------
thomaseliot
26-Mar-08, 23:48
If you use PS2 for VN10, it is logical to go without any transformer nor PSU1-VR, for a very compact amp. Use your 12-0-12 PS for +5V and active pre: just add a PS317-P to get +5V from +12V.
PS317-P has three pins (in-out-gnd), you can mount it directly on Truepath, on the input pads for +5V and AGND (J1): cut the third pin (input), while output and ground are soldered in J1. Then connect +12V and 0V to the small PS317 pcb (on input and ground). :)
Ok Giovanni, why I didnt though those options before the order the parts! [:I], so, now I have the PSU1-VR free if I go with the PS2 and PS317.....may be for the next Truepath !:D
About my question : Looking the Truepath assembly instructions, it says that for use with 4 ohms loads and voltage higher than +-50 V (My case), it is necessary to update some components. The issue here is that it not says "wich" components to change, and their values...It could be the resistors for the current limiting ?
thomaseliot
27-Mar-08, 13:46
PS317 costs 2.5 euro, but if you have space use half of PSU1-VR.
Resistors to replace for 60V rail are for current limiting. Search Tim's (Audiophool) thread "Optimizing Truepath".
I can see that the PS2 its Dual ...so, I will use one half, and in combination with one half of PSU1-VR....so, I will have another kit PS for the next Truepath...just order the PS2....I think that it would be the PS2 P+P right ?
P+P indeed, it is also available in single... But if you need another one soon I'd get the dual version...
------X-max. can be several meters on any driver, too bad it can be done only once...------
yep...looking for the second Truepath later..:D
quote:Originally posted by V-bro
[br]
That 4080 meter seems like a good bet, I was contemplating on buying one myself, unless there's a good chinese alternative...[:p]
------X-max. can be several meters on any driver, too bad it can be done only once...------
Time to tell you about the Chinese LC meter, i've just got and tested it and....well...it works very well but only above 25uH... It's a decent multimeter but it doesn't go low enough for my (and your) needs. I've to find one that can measure very low impedance value but at this point, i don't think that is going to be cheap. In the end otherwise, for this kind of application maybe it's enough to calculate inductance by toroid type and number of turns...as said by Thomaseliot [:I]
Dammit...i have to sell it on ebay now.
See you
Gianluca
audiophool
07-Apr-08, 15:02
quote:Originally posted by abelma
[br]
...
Looking the Truepath assembly instructions, it says that for use with 4 ohms loads and voltage higher than +-50 V (My case), it is necessary to update some components. The issue here is that it not says "wich" components to change, and their values...It could be the resistors for the current limiting ?
Hi abelma,
Here's the schematic, PCB overlay, and SMT parts sheet for Truepath 60V CD 4 ohm, which I understand to be your intended configuration.
http://base.google.com/base/a/3455296/D12188031427675449194?hl=en_US
Actually it's optimized for 45VRMS transformer which comes out at 61V rails.
If you need to get the additional SMT parts for optimization (and optionally a few extra goodies), I can send them to you. Please take a look at http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1597&whichpage=2
Also, since you are using such a high rail voltage, I would encourage you to use some sort of rail stabilization such as dummy load or shunt regulator at approx 65V.
Regards,
Tim
Hi Tim.;Thanks a lot!
actually I am planning the assembly because I will install a preamplifier to build an integrated amp.
The selection it is the aikido octal. This preamp has more output level db than a cd player. So, I should make the reconfiguration and the values parts in the truepath. Looking for wich tube will be my choice and then see how much preamp level amplification. Keep you posted today.
Regards,
Abel
Hi again Tim,
Ok, my preamplifier will have a gain of +20 dB, that means if I am right, 11.2 vpp.
The source of this preamp will be 2 vpp....so, what would be your recomendation with a VNN, VPp of 60 Vdc for the truepath ? Thanks a lot
audiophool
13-Apr-08, 18:13
abelma,
By my calcs, 20dB means a factor of 10, ie, 20log Gain = 20dB => Gain = 10^(20/20) = 10
If you have 2Vpp into the preamp then you have 20Vpp on the output of the preamp. That means you will have (max) 20Vpp into your Truepath. Is that correct?[?]
Regards,
Tim
audiophool
14-Apr-08, 02:42
abelma,
Truepath requires 4Vpp into the input op-amp. You have to reduce 20Vpp to 4Vpp. This means 20log 4/20 = -14dB. This can be done with Rin=49.9k and RF=9.76k.
Unfortunately, such large gain followed by attenuation is probably going raise the noise floor of your system. Would it be possible for you to omit the preamp? In this case you only need 6dB gain on the 2Vpp from your source. This could be done with Rin=24.9k and Rf=49.9k.
Regards,
Tim
Thanks Tim,
Ok, now I understandt more about this:). But, it should be better in this way to have less noise ?..I remember in my amp10 when I did the contrary having more gain like 1.5, and after that have more noise floor.....My doubt is, what do more floor noise, high gain, or high Rin = input impedance ?....What should be the problem having a Rfdbk of 10 K ?
Another idea... I have in mind to try an input line transformer at the preamplifier input and/or amplifier input. Having a talk with the guys from Lundahl they say that having a input bias of 2.5 vdc in the amp it is not suitable because it will not have a good freq response.....So, anyway, I could use the transformer in 2:1 and reduce the gain somewhere....what do you think?
Ah!..and about using the preamplifier I would like to try a tube preamp to see :D
Hello again guys,
Ok, start the soldering process..finally!
I have a few questions about C104, C204, C8. those caps are noted as 47 uF x 25V.
I can see the caps that I have, and the caps on the photos fo the assembled truepaths from anothers members, and, it seems those are bigger in dimensions. They have more value?
audiophool
19-Jun-08, 03:13
The type of 47uF caps that are shipped with Truepath varies. Usually they are brown and 105degC. Sometimes they are blue and 85degC. Both types are a little smaller than the PCB footprint.
Thank you Tim.
By the way, I (we) appreciate your help to assembly the truepath. I am reading your posts,slowly, and very helpful. Keep you posted on my advances. Thank you again
audiophool
20-Jun-08, 15:43
Hi abelma,
Your appreciation if much appreciated.:) I would be really interested in hearing what you find particularly useful and what you would like more help with.
I'm interested to follow your progress with Truepath; please post regularly.
All the best with it.
Regards
Tim
Thanks Tim,
I can see that the soldering process is a little more difficult that the AMP10. I had a few difficuly solder point with the chip, it seem that my soldering station is not so poweful, it is a Velleman 48 W regulated temp.
I will assembly this amp with some updated components selected from my experience with the AMP10. Mundorf silver/oil input cap, Shinkoh input and feedback resistances, and bigger toroids. Also, I will use a switch power supply 800w for audi purposes. After that, I will assembly a tube preamp (Aikido octal and nonal), but after a lot of time of use with the truepath connected from my dac(Paradisea+) as source. Last component in the chain, the Triangle Celius Es, amazing speakers, it seems to never stop improving, it is directly proportional of the quality of the elctronics connected. I' ll keep you posted this week end with some progress. Regards.
Abel
andrewbee
20-Jun-08, 18:27
Abel,
I think you need to be very careful with the Truepath. It is a 4 layer PCB and is mostly surface mount components. The inductance and capacitance of components in this kit may be of some significance. I think you should build it stock and verify its operation before you begin changing components.
It is always best to build a standard configuration and verify it before you change anything and when you do change something test after each change to again verify operation.
Andrew
Hi Andrew,
You are right, I will not change any recomended value of the components, only the kind or brand of resistor and input cap. The toroids will have the same inductance, but 130-2 size. I will keep you posted if it works :D..or not!..regards
Abel
Hello, assembling the truepath and I have question here.
Tim, at your optimized circuit R4=422 K, R6=464K
I have only in the provide bags with the kit for R4=392K adn R6=422K.
No R=464K.
I should use the R4=392K and R6=422K ?
Remember that I will use VNN=VPP=60VDC
Thanks, and soldering others compponents for waiting for your answer
audiophool
21-Jun-08, 18:48
Abelma,
The optimized schematic that I prepared for you uses optimizing components that are not included in the basic Truepath kit. Follow the links below for more details.
This is what I said:
quote:
Here's the schematic, PCB overlay, and SMT parts sheet for Truepath 60V CD 4 ohm, which I understand to be your intended configuration.
http://base.google.com/base/a/3455296/D12188031427675449194?hl=en_US
Actually it's optimized for 45VRMS transformer which comes out at 61V rails.
If you need to get the additional SMT parts for optimization (and optionally a few extra goodies), I can send them to you. Please take a look at http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1597&whichpage=2
I figured that you got the components yourself and that's why you didn't ask for them! Sorry about that!
If you don't want to use the optimized components, then you can follow the AI for the basic Trupepath configuration which Thomaseliot prepared and posted here http://digilander.libero.it/epiworkr/TruePathAI.pdf
Regards,
Tim
Ok, thanks and sorry, I didnt read the post!
But, reading the original truepath assembly manual, for the voltage rail that I will use (Aprox 60 vdc), those resistances coming with the kit should work?
My soldering with smt are not very good[xx(]... I wonder if this amp will work.:D
Well. I have missing components. The R217, R117, R221, R220, R121 and R120.
The strange thing is that those missing components are not listed in the short and long BOM downloaded from the web site ! Asking the parts to 41 hz right now.:(
thomaseliot
21-Jun-08, 23:38
abelma,
R221, R220, R121 and R120 are pieces of wire, just connections between two points: use cutted legs of resistors.
R217 and R117 are the two big 5W ceramic resistors.
Thanks Thomas of that data!
But R217 and R117 are missing...and there are not listed at the BOM short and long. >>>>>> YEP...there are on the both BOM...I should not drink wine and solder the kit at the same time!:)
Ok, waiting for the R217 and R117 from Jan, but, the Truepath is ready.
Now assembling the power supplies.
Question , how much current draw for VN10 ?
I am planning to use PS2 to supply VN10.
audiophool
23-Jun-08, 01:39
VN10 draws 200mA
Thanks Tim....Can I do the first power up tests without R217 and 117? Because I will not connect the speakers yet.
quote:Originally posted by abelma
Thanks Tim....Can I do the first power up tests without R217 and 117? Because I will not connect the speakers yet.
That might not be a good idea as the capacitor (C109,C209) and the resistor (R117,R217) form a filter, that prevents the amp to oscillate ([u]especially without load!</u>)
/Benn
audiophool
23-Jun-08, 19:05
Abel.
You can use a dummy load instead of speakers. Do you have a pair of 5W or more 4 to 10 ohm resistors. It would be fine to use these instead of speakers without the zobel. Watch the VN10 current. Once you see current flowing in it then you have gone as far as you can so switch your amp off. Suggest you don't do the zero offset adjust until the zobels are fitted.
Regards,
Tim
Ok, so, mmmmm...I might better wait for the resistances.
How connect the PS2 to have VN10 from the main power supply VPP-0-VNN?
PS2 share the input and output ground, un the regulated V+ to produce the voltage required, 10 volts in this case. Should I connect the Input + to the "0" of VPP-0-VNN ? And the ground to VNN ? Regards
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