Pluging a turntable to Amp6-BASIC

[b.desmarets]

Hey all,
I've bought, months ago, an Amp6 Basic, in order to start a small DIY project.

Actually, the final goal is to use the amp with volume control, PS and battery (everything housed in a nice case), with a pair of speakers, playing my vinyls. And it's about this last part I'm now needing help : the turntable, and more precisely, the need of pre-amplifying its signal. I've only understood that I need to get a pre-amp, to amplify, adjust and correct the signal, but could you give me more information about the practical aspect of it? What specifications of the pre-amp do I need to check? Where does it have to be soldered on the amp? And do I need to configure it or just sold it? Such elementary questions I prefer to get from humans than articles...

I've only been advised by a friend, to get the "Phono-M pre-amp" from Thel Audio : here with its transformer : here

Thanks in advance for all the help. And, as I post here my first message, thank you for the precious help you've already given to me.

Baptiste.

[gnome]

Hey all,
I've bought, months ago, an Amp6 Basic, in order to start a small DIY project.

Actually, the final goal is to use the amp with volume control, PS and battery (everything housed in a nice case), with a pair of speakers, playing my vinyls. And it's about this last part I'm now needing help : the turntable, and more precisely, the need of pre-amplifying its signal. I've only understood that I need to get a pre-amp, to amplify, adjust and correct the signal, but could you give me more information about the practical aspect of it? What specifications of the pre-amp do I need to check? Where does it have to be soldered on the amp? And do I need to configure it or just sold it? Such elementary questions I prefer to get from humans than articles...

I've only been advised by a friend, to get the "Phono-M pre-amp" from Thel Audio : here with its transformer : here

Thanks in advance for all the help. And, as I post here my first message, thank you for the precious help you've already given to me.

Baptiste.

The question is why on earth would you want to ruin the amp6 by playing vinyl on it??

But very well, it's your business why you want to listen to crackles and pops, however you need to understand why you need a special preamplifier for listening to phonograph records and why it is such a retarded format
read this:
http://en.wikipedia.org/wiki/RIAA_equalization

So pretty much any pre amplifier with a phono input will do because they have to be able to deal with riaa equalization by definition, you could use a dj amplifier for simplicity's sake, that phono pre amp that was suggested to you is probably just fine, but I have to admit that the input and output tabs seem very confusing, you will have to ask them for instructions.

[krilli]

It turns out that the exact method by which vinyls render music listening especially pleasurable isn't something that can be measured ...

The phono preamp and correction circuit doesn't need to be soldered on the amp. It can be in a separate housing. It's simply connected somewhere on the way between the record player and the amp - you can place it where you like.

[b.desmarets]

Okay, thank you very much guys.

Would it be a good idea to enclose the pre-amp in a special housing, so I could use it later if I get another amp? And, for this project, can I set up a RCA switch at the amp input, to plug on a side, the amp and on the other one, my iPod? And finally, can you confirm that the pre-amp doesn't need to be powered? It only transforms the signal by reducing or boosting intervals of frequencies, without the need of electricity?

[krilli]

Yes, a separate housing for the preamp works fine.

No, the preamp does two things: It boosts the very low signal from the turntable to line-level, and it corrects the frequency response. As far as I know, the boosting needs to be done with an active circuit.

To show an example, here's the Boozhound Labs JFET Phono Kit: http://boozhoundlabs.blogspot.com/p/...reamp-kit.html

It's very simple. I don't know if it's any good - I show it only to give a picture of the essentials.

[V-bro]

Vinyl records can sound very very nice. I have m trusted old Pioneer C21 preamp for that purpose. Indeed you need EQ-ing (called RIAA) which needs to match the response of the pick-up to make it somewhat linear.

I don't see why listening to well EQ-ed vinyl would be any worse than listening to L/C filtered square waves??

[b.desmarets]

Let me reformulate the question about a separate housing for the preamp : I guess it is possible to put the preamp in a different box, but is there a interest for it? Like using it with other amp? If the features are too restrictive, then I would prefer to put in the same box.


And indeed, the preamp needs to be powered... Then, is it possible to use the same power supply as the one for the power amp?
I guess, as the power source of the preamp's transfo might be the same as the amp's one, maybe it is possible to mount both devices in series? (I'm just calling upon my skills, which in this case, look more like preconceived ideas...)

Thank you.

[Scratchy]

I like what you are doing here, and I think I understand your goal.
You are building a purpose built phono amplifier, in the sense that you want 3 pieces - a turntable, an amplifier and speakers.
Nothing less, nothing more.

There is a pleasing retro quality sound, listening to vinyl.
Not everyone is into over-compressed CD/MP3 digital sound.

Based on this, yes you can build the phono pre-amp and AMP6 all in one small enclosure.
You will have RCA connectors for the phono-in and some type of connector for speaker output.
You will also require a power supply input connector, depending on what type of PS you will be using.

[b.desmarets]

Thank you Scratchy.
So, talking about only one PS, I guess it's possible to use the same for both amps?
And what about using a RCA connectors switch, to be able to plug the iPod directly to the amp without going trough the preamp?
I'm gonna try then to draw a scheme.

[V-bro]

Ah yes, sorry for not attending to the initial questions you had to open this thread... I don't recommend to use the same PS voltage because it will raise the noise level, or even hum like crazy if you are unlucky. Looking at integrated amplifier designs you ALWAYS see a separate transformer winding and rectifier bridge for the preamps and power amp circuits. That wasn't done to make them just fancy as most of them are cut on investments internally for as much as possible.

Same box, fine!
Same PS, NO!