Could a tube buffer be useful for a Non-Inverting Gainclone?

[Bas Horneman]

Why is a tube buffer used for inverting gainclones and not for non-inverting gainclones...?

[Joe Rasmussen]

Originally posted by Bas Horneman
Why is a tube buffer used for inverting gainclones and not for non-inverting gainclones...?

Hi Bas

Try this link, it should answer it adequately:

http://members.ozemail.com.au/~lisaras/design.htm

Also find the thread Tube with Power IC Output Stage - JLTi where these are covered in detail.

You are right, with non-inverted implementation a buffer is not strictly a requirement.

Joe R.

[Bas Horneman]

Thanks Joe...

I guess bottom line is... if I understand correctly ....the Inverted gainclone practically NEEDS a buffer because of the way the feeback is applied.

But there is no harm in trying to play a little with a tube buffer to maybe voice a non-inverting gainclone is there?

The reason I ask is that I am thinking of building a 6c19p cathode follower preamp for the gainclones kits I got from BrianGT.

Cheers,
Bas

[Peter Daniel]

I find the influence of the buffer even more rewarding with NI GC. The only buffer I'm using is S&B TVC stage and the improvement in sound was as big with NI amp as it was with Inverting (or maybe even more). It seems like this stage was made for GC.

This is not saying that the amp alone doesn't sound good. It's just that adding TVC takes it one step further (sonically).

[Bas Horneman]

S&B TVC stage

Hi Peter,


Unfortunately 6 * S&B TVC stage is out of my price range ;-)

But I have a transformer coupled preamp...www.raleighaudio.com
....loverley...am very curious how it will sound with gainclones.

Cheers,
Bas

[coredump]

I cannot comment on tube buffers, but I've been using my GC with an old Nac 32-5 for about two weeks now. I am really pleased with the results. The NAC is quite smooth for a Naim amp, and the forward prasentation/fine dynamics is quite similar with both. The NAC adds some punch and sense of space.
As a side effect, it solved my phono pre problem as well.

Probably still too harsh and "sand"-sounding for you.

[Joe Rasmussen]

Originally posted by Peter Daniel
I find the influence of the buffer even more rewarding with NI GC. The only buffer I'm using is S&B TVC stage and the improvement in sound was as big with NI amp as it was with Inverting (or maybe even more). It seems like this stage was made for GC.

This is not saying that the amp alone doesn't sound good. It's just that adding TVC takes it one step further (sonically).

Hi Peter

Thanks for confirming that as I have no way currently to check it out. I suspect that like you I'm not stuck on either IGC or NIGC, except IGC has a more rational reason for a buffer, but that is all. The end results matters more.

Joe R.

[Sheldon]

Originally posted by Bas Horneman
Thanks Joe...

I guess bottom line is... if I understand correctly ....the Inverted gainclone practically NEEDS a buffer because of the way the feeback is applied.

But there is no harm in trying to play a little with a tube buffer to maybe voice a non-inverting gainclone is there?

The reason I ask is that I am thinking of building a 6c19p cathode follower preamp for the gainclones kits I got from BrianGT.

Cheers,
Bas

Got a schematic you're thinking of? I'm curious to do something similar, but need and example to work from. I don't have the experience to do much more than make minor changes in component values.

Sheldon

[Bas Horneman]

Hi Sheldon,

Here is a description for a cathode follower.
http://www.tubecad.com/october99/

Copyright Tubecad

I don't know the best operating points for a 6c19 ...You could use one half of a 6080 or 6AS7 as well..(These tubes are more commonly available...especially in the USA)

I reckon low voltage around 200v on the plate and around 40mA would be a ballpark figure.

[fdegrove]

Hi,

Any reason why you can't use the one for the IGC?
Or the one Moamps designed with the CCS in the tail, for instance?

Cheers,