What stereo Pot for Gainclone?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Can anyone recommend a good stereo pot for volume control for a gainclone? How much affect on sound does Pot selection make?
I will giving this amp signal from a laptop or Ipod if that makes a difference.

It's just a brianGT two channel 3886 with the snubber.

I'm just looking for a really good sounding amp for casual listening to a variety of music. Prob run a M T M style speaker. Maybe a powered sub as well.
 
Is it Inverted Gainclone ??
or the 'standard' from National datasheet NON-Invereted config ??



For the inverted, the Thorsten Loesch variant, that was very popular, you can get issues using one pot in front of input

For non-inverted this issue may not be quite as big.

Any case, when you do put one pot in front of one power amplifier input, you have to consider the in & out impedances.
As bringing another 'resistor' into play, in this case the potentiometer, will effect the signal & often frequencies, that do reach the input transistor.

To overcome this, many Gainclone builders use Buffered Input of the power chip.
This is seen BOTH in Tube Buffered gainclones and in JFET Buffered gainclones

Some more good reading here, at Nuuk website:
Building a buffered Gainclone chip amp
Building a *vale-buffered Gainclone chip amp

* should read Valve-Buffered Gainclone = Tube Buffer

Regards
Lineup
 
Hi,
a buffer added to the source output that can drive any combination of cable and attenuation pot helps sound quality.
A buffer at the input of the chipamp allows any attenuation pot to perform without having a deleterious effect on the input of the chipamp.
Omitting either of these buffers will make selection of the attenuator and the design of the chipamp considerably more onerous. Many more compromises must be accepted if you go this route in search of improved sound quality.
Read Peter Daniel for his views on minimalist interconnection.
 
What other option do I have to control to volume? These are the Non Inverted 3886 kits from BrianGT. I am running just the one power supply but I have another power supply kit. Are you guys saying that I should use one power supply for each of the chipamps but use the same transformer to power each power supply?

I'm an electronics idiot and can say I don't really understand how any of this works, I just wanted to build a good sounding amp. The BrianGT kit instructions talk about putting a Pot on the input to control volume I did wonder why you could not put the pot on the feedback circuit instead of the feedback resistor and use that to control the amp gain and therefore the volume.

Either way if someone could just tell an electronics idiot what exactly to do to finish this amp project I would really be in your debt. I thought my only option was to use a pot on the input.
 
read the datasheet.
The stability of the chipamp is affected by the gain.
National say it is stable if the gain is over 10 (+20dB).
That would be the minimum gain you could use for minimum volume.
It would be just 6dB to 12dB below maximum.
= broken eardrums or broken speaker or broken amplifier or any combination thereof!
 
Well I guess I decided not to use a Pot on the input if I don't have to.
If I'm using an Ipod to provide my signal and it has a volume control, I can just use that correct?


Also, the torid transformer I have has 16.2v secondaries. That will still work right, it just won't have as much wattage output? I don't need it to be exceptionally loud. Or do I need to get another transformer?


I was going to hook it up like this. Apex Jr Torid hookup
 
DC Dave said:
I have had good luck with this one from Jaycar. The affect on the sound is similar to any of the components in the circuit, and is very subjective. You might also want to try the ~$5 Alps pot from Radio Shack for comparison.

http://www1.jaycarelectronics.co.uk...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
An externally hosted image should be here but it was not working when we last tested it.


small for stereo looks ideal to me but is there a source in US?

gychang
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.