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A place to discuss member's DIY audio projects & post pictures/schematics. NOTE: There is a limit of 2MB per attachment, and a maximum of 3 attachments per message. If you need to post more than 3 attachments, just add another message.
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Re: Musician's Amplifier

February 11th, 2019, 4:39 pm

Roscoe Primrose wrote:I've got an NOS pair of UTC LS-61s I've been saving for a project like this. One of these days....

Roscoe


Well, there you go! Give it a shot, I think you'll be pleasantly surprised.

Re: Musician's Amplifier

March 2nd, 2019, 11:49 pm

Another update. It seems that I ordered a pair of Heyboer reproduction Peerless S-265-Q's! I spoke to them on the phone several weeks ago and they said they'd email a PO for payment but they never did so I thought they'd forgotten about them. But here they are! And boy, they're hefty. Up and running now in an original Williamson circuit with 5881's or KT66's. They are really lovely, smooth and rich, like a nice single-malt. Lots of texture in the music, plentiful bass, but no ringing or peaky-ness that I can hear. Just very easy and musical. Heyboer did a nice job with these. I paid $400 for the pair plus shipping, but I told them to leave off the screen taps. With those I think they said $220 each. I think for an original Williamson project you can hardly do better than these.

There's a mate for my Patridge WWFB 0,95 on eBay now, auction ends tomorrow around noon. I was very tempted but I think I'll save my money. It'll probably go for more than I paid for these. Anyone wants to grab it, I've got a mate for it sitting here. ;-)

Re: Musician's Amplifier

March 2nd, 2019, 11:58 pm

You might want to look in the wiki on what Brian May used for amplifiers -

https://en.wikipedia.org/wiki/Brian_May

Re: Musician's Amplifier

March 3rd, 2019, 1:08 pm

Okay, that Partridge in eBay is now up to $1096.00 Don't think I'll bid. In fact, I think mine will be going up for sale soon. That'll pay for all these other transformers I've bought... ;-)

Re: Musician's Amplifier

October 12th, 2022, 7:00 am

All,

Apologies for reviving an old thread, but I just wanted to post a followup on this project. Grover shared his experience, advice, and recommendations with me over the past couple of years and I finally completed a pair of "Gilded Lily" versions of the Sarser and Sprinkle "Musicians Amplifier" using the Heyboer reproduction Peerless S-265-Q output transformers like the original. Part of the reason it took me so long was it was a year wait on the transformers. They are still breaking in, but are wonderful sounding amplifiers. PP KT66 Williamson design.

BTW, the basis is an article in Nov 1949 Audio Engineering magazine (updated to UL operation in a followup article in 1952). Grover shared his current schematic reflecting some updates to improve stability and feedback network values for the transformers. Used modern parts including PP DC-Link capacitors and ultra high reliability KEMET 600V electrolytic capacitors in the power supply (increasing storage value over the original). Also used CDE 942C/1000V PP coupling caps. Amazing that a 70 year old amplifier design can sound so damn good.

20221007_113740.jpg
20221008_224710.jpg


David

Re: Musician's Amplifier

October 12th, 2022, 9:03 am

David:
Another example of your exceptional craftsmanship. Kudos on the result.

Tom

Re: Musician's Amplifier

October 12th, 2022, 10:39 am

Got to love mirror image monoblocks!
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