My own Pumpkin preamp - Construction

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Thanks Jacco,
I was a little Leary of DIYCLUB.BIZ, but they were the only ones I could locate the R cores from. They came through ok, the web site does not offer an option for size so you have to include that info in an email. The closest I could find was one with 45 and 50 volt secondaries, they make the shunty run a little hot, I will probably need to add extra ventilation in my case. I have been waiting for Twisted Pear Audio to complete their AC1 controller and new Joshua tree attenuator to finish my pumpkin. I did Receive a New Haven display and rotary encoder so I can begin designing the front panel.

Bill
 

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The Hong Kong page doesn't open for me right now, but I recall that the closest one they list is a dual 50-55Vac model.
They offer others, besides the listed ones ?

R-type transformers have the primaries and secondaries wound on separate sides of the core.
Unwinding or adding windings is even easier than with regular toroidals, as is exchanging the outer wrapping.
 
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TO-220 heatsinks again

Just to bring this up again, since it was here before...

Did anyone in North American come up with a good source for TO-220 heatsinks? - best I can figure max 33mm X 15mm, to dissapate 10W needs to be tall.:flame:

I could grind down something close.

Mike
 
Getting back to this project, trying to complete the preamp enclosure. First I had to complete the front panel. It has to receive the Placette LCD display, the optical encoder (Volume Control) and the source selector rotary switch. Problem was that I built the enclosure using multiple layers of wood and that the LCD has to be closer to the front surface than 1.5'', and that the encoder and switch shaft are too short also.

So I needed to dig some cavities to receive these parts. Here the front panel, back and front view
 

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Me and a few friends, with did our own version of it. There is no DIYer version available. The closest thing would be the Joshua Tree attenuator from Twisted Pear: http://www.twistedpearaudio.com/control/jt.aspx

Here a detailed view of the front panel. Still some finishing to do, but looking good already.
 

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Thanks for the great pics of your enclosure. It looks fantastic. I am thinking about a wood/alu hybrid and this is great inspiration. I'm not quite up to that level of finish but it gives a really good idea of what's possible given the right tools and skills. Keep 'em coming.

I was curious why you said the original Surplus Sales HS501's did not fit. I don't have my boards yet, but I dry fitted the 501's on a paper template and all seemed well except for a 1/4" overhang in width. Was it because of the Auricaps thickness?

Tom
 
tms0425 said:

I was curious why you said the original Surplus Sales HS501's did not fit. I don't have my boards yet, but I dry fitted the 501's on a paper template and all seemed well except for a 1/4" overhang in width. Was it because of the Auricaps thickness?
Algar_emi,

My bad, as I see this was actually "divsw" and "wirewiggler" that were referring to this.

Guys, can you clarify on the fit of those 501's? I thought I had a winner there based on my template.

Tom
 
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