6CB5 AMP BUILD.

[tubem]

I have just finished building a version of Thomas Mayer's 6CB5 AMP,I'm really impressed with the sound of it, as a few of my friends were amazed how well it turned out. I'll be sending pictures as soon as I figure out how to do that again,sorry.

[vinylkid58]

If your pictures are really big, just post them up here and ask a mod to re-size them.

jeff

[tubem]

Here are the pictures

[vinylkid58]

Looks great! Love the shape of the 6CB5's.

How about some details?

jeff

[Vinylsavor]

Hi!

Nice amp! Congratulations! I'm glad to read that you like the sound!
Those ST-shape 6CB5 look great. These are quite difficult to find actually, while the straight glass 6CB5A is very common.

Best regards

Thomas

[larryldspkr]

I had the pleasure of listening to this amplifier for a couple hours last night on my recently completed Tang Band 1772 speakers. All I can say is WOW this thing sounds AMAZING!!!
Great job Jim on the build and thanks Thomas for a great design! The problem now is that I'm spoiled and I WANT ONE!!! lol This is definitely the "cure for the common amp"!!

Larry

[Vinylsavor]

Hi Jeff,

Originally Posted by vinylkid58

How about some details?

You can find the schematics for 6CB5A amps on my blog. Click on the label 6CB5A for all posts related to this tube. The amp looks like the RC coupled version. There is also an interstage transformer coupled one which is a bit more sophisticated. Don't hesitate to ask me if you have any questions. I can also provide parts if you have difficulties to find what is needed.

Best regards

Thomas

[Vinylsavor]

Hi Larry

Originally Posted by larryldspkr

The problem now is that I'm spoiled and I WANT ONE!!!

That 'problem' is easily fixable

Thomas

[vinylkid58]

Thanks Thomas.

jeff

[tubem]

Yes Thomas is right, it is the RC version which simply means it is capacitor coupled to the 6CB5 instead of the interstage transformer, this is the lower cost version, but not in all respects the power supply is a little more involved in that it has two pie filter sections with three banks of filtering all bypassed by quality mpp caps. The plate voltage on the 6CB5'S is 400v @70ma each, the 6N7'S are at 200v. All wiring is point to point with connections as short as possible, the actual chassis size is 17''x10''x3'' and it weighs approx 50lbs. I can tell you the extra choke and filtering is well worth it because this amp is dead quiet and that really also impressed everyone at the amps debut Thursday night. Oh and yes the old st shape 6CB5 are rare but I'm fortunate to have a dozen of them and I'll be looking for more, I'ts funny I had these tubes probably 15 years and never would have done anything with them had I not seen Thomas's blog so thank you Thomas!