Tube with Power IC Output Stage - JLTi

[moamps]

I've been completing the construction of my hybrid power amp with an E88CC tube as a buffer. I expect to have it finished in a couple of days, do some final measurements and then I plan on doing some listening tests and compare it with the small power amp Aleph3 I built some time ago. I could present the results of those tests here if there's enough interest. First, a few pics:

Regards

[moamps]

2/3

[moamps]

3/3

[fedde]

Wow. Looks superb !

Fedde

p.s. My birthday is 28 september

[king30]

I would definitely be interested in hearing your results.

[planet10]

Gorgeous :^)

dave

[ultrachrome]

I've noticed all the IGCs have pots. Is the point of the pot to eliminate the need for a preamp?

I don't really have a need for a pot on the amp as I wish to continue using my preamp and ulitmately active crossovers. Is it difficult (for an amateur) to remove? Is driving it with a preamp a problem? I have a Foreplay but I'm reading Audio Reality and I'm thinking about buiding the GG pre.

I've been eyeing this project for a while and love the idea of combining tubes with ICs.

Thanks.

[Joe Rasmussen]

moamps wrote

I've been completing the construction of my hybrid power amp with an E88CC tube as a buffer. I expect to have it finished in a couple of days, do some final measurements and then I plan on doing some listening tests and compare it with the small power amp Aleph3 I built some time ago. I could present the results of those tests here if there's enough interest. First, a few pics:

WOW! Well done!!!

Yes, do please submit your test results. And I can't wait to hear your report on what you're going to hear.

Regards

Joe

[Joe Rasmussen]

Originally posted by ultrachrome
I've noticed all the IGCs have pots. Is the point of the pot to eliminate the need for a preamp?

I don't really have a need for a pot on the amp as I wish to continue using my preamp and ulitmately active crossovers. Is it difficult (for an amateur) to remove? Is driving it with a preamp a problem? I have a Foreplay but I'm reading Audio Reality and I'm thinking about buiding the GG pre.

I've been eyeing this project for a while and love the idea of combining tubes with ICs.

Thanks.

You don't actually need the pot IF the IGC is buffered - indeed you can then use it as a Power Amplifier, so wire it straight into an RCA socket. Instead of the pot put a 47K or 100K resistor.

The gain is quite high, in this DIY Tube Gainclone the gain is 33dB and that means a preamp is superfluous. Do as moamps has done (see his wonderful pics) and you can see his input selector switch, I think it looks like 3, wired before the pot, and... you have a INTEGRATED amplifier.

The original IGC will not work properly without the pot, but this one will, so it's up to you.

Joe

[pedroskova]

Originally posted by Joe Rasmussen


The original IGC will not work properly without the pot, but this one will, so it's up to you.

Joe

...why wouldn't just putting a 100kR from input to ground work in the original?