new gainclone w/ reg supply (pics)

[oldfatbubba]

...brought into this world at about 12:30 AM EST

LM3875 with dual regulated supply using LM338

also see...

http://home.comcast.net/~eric.ericks...gainclone2.JPG
http://home.comcast.net/~eric.ericks...gainclone3.JPG
http://home.comcast.net/~eric.ericks...gainclone4.JPG

feedback is always appreciated...

Regards,
Bubba

[davidlzimmer]

Very very nice!!!!

What are you using as a source?

[oldfatbubba]

Thank you.

The source is a homebrew tube preamp. It's a simple, SRPP topology using 12AU7s (or whatever variant that happens to be handy). It has clean DC on the filaments and a regulated power supply.

Here are the guts....

http://home.comcast.net/~eric.ericks...ne/preamp2.JPG

The signal caps are Multicaps but the rest of the parts are mediocre. Regardless, it sounds good.

[davidlzimmer]

Even sweeter!!!!! Very nice!!!

[DocLorren]

Very nice layout with short signal paths. Do you like it? :-)

[oldfatbubba]

Originally posted by DocLorren
Very nice layout with short signal paths. Do you like it? :-)

Thank you kindly for the compliment, Doc. So far yes, I like it a lot. I'm a bit surprised how good it sounds, really.

I'm thinking about making a top cover from tempered glass and using 1/4" spacers for ventilation. Thoughts?

Regards,
Bubba...

[davidlzimmer]

I like the idea of a glass top. If you listen at moderate levels, you will probably not have a problem with heat. IMHO your heatsinks are on the skimpy side. So, beware of trying to reproduce rock concerts in your living room.

Are you new to gainclones? If so, you have a pleasant surprise in store. The burn in period! The sound will get sweeter and more "musical'.

Cheers!

[oldfatbubba]

Originally posted by davidlzimmer
IMHO your heatsinks are on the skimpy side.

Perhaps, but they barely got warm after 12 hours. I was somwhat worried about the size of the regulator heatsinks but they were even cooler!

Originally posted by davidlzimmer
Are you new to gainclones? If so, you have a pleasant surprise in store. The burn in period! The sound will get sweeter and more "musical'.

This is the first Gainclone though I've build several tube/valve based power amps, though.

RE: burn-in, what do you recommend? I was contemplating either:
1) using a signal generator at, lets say 1 kHz,
2) tuning between two FM stations,
3) pink noise software such as....

http://www.sharewareconnection.com/t...-generator.htm

[kec]

Originally posted by davidlzimmer
IMHO your heatsinks are on the skimpy side. So, beware of trying to reproduce rock concerts in your living room.

I think those heatsinks are fine - I have some of those myself. But, on my LM3875 GC, I use only an aluminum angle and mine barely gets warm at moderate levels.

Nice job Bubba!

[Hartono]

Very neat , uncluttered without being over the top with expensive case material, congratulations !! and looks very good.

That perforated board supply is very neat ! I with I could do perforated board that looks that good.

Hartono