JC-80 eBay PCBs & Power Train

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#282
Here is modified pcb of Attenuator Buffer: repositioned some parts and new GND tracks.

Hi pinnocchio

It is very long way to finish The Preamplifier. I need to design few pcbs else: Attenuator Driver, uController (including front panel pcb for encoders, switches and LEDs). Many months ago I started to build Krell KSA-50 Mk2 amplifier. Up till now I have all parts of housing (many alu parts and huge heat-sinks). I slowly assembled the housing but before finish it I need to soldering all pcbs and design other three pcbs. Both devices (The Preamplifier and KSA-50) I want finish nearly in the same time to use them together. Additionally from few months I design and still testing many configurations of music server (simply PC motherboard with very complicated DAC). The Music Server is commercial project and I make it with my friend together. So as you know I am very busy from few months and the state will exist till finish all three devices. But I will assembled The Preamplifier step by step so I hope to publish some photos in this year already.
 

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#283
JKoch said:
Here is modified pcb of Attenuator Buffer: repositioned some parts and new GND tracks.

Hi pinnocchio

It is very long way to finish The Preamplifier. I need to design few pcbs else: Attenuator Driver, uController (including front panel pcb for encoders, switches and LEDs). Many months ago I started to build Krell KSA-50 Mk2 amplifier. Up till now I have all parts of housing (many alu parts and huge heat-sinks). I slowly assembled the housing but before finish it I need to soldering all pcbs and design other three pcbs. Both devices (The Preamplifier and KSA-50) I want finish nearly in the same time to use them together. Additionally from few months I design and still testing many configurations of music server (simply PC motherboard with very complicated DAC). The Music Server is commercial project and I make it with my friend together. So as you know I am very busy from few months and the state will exist till finish all three devices. But I will assembled The Preamplifier step by step so I hope to publish some photos in this year already.
Click to expand...

Take your time, you'll be more than rewarded by the sound of this preamp!

Post some pictures of your build process as it will be very interesting to see.

Ciao!
Do
 
#287
JKoch said:
Hi ticknpop

I have bought Hitachi 2SK216/2SJ79 on ebay:
1pair or 2pcs Transistor Hitachi to 220 2SJ79 2SK216 J79 K216 | eBay

I hope they are genuine Hitachi. Building clone Krell KSA50Mk2 I was finding Toshiba 2SC2238-Y/2SA968B-Y. I examined and checked many pictures and offers from: electronic distributors, ebay and Chinese alibaba sellers. All of them offered 2SC2238-Y/2SA968B-Y in black TO-220 case. But original Toshiba P-channel/PNP TO-220 transistors were encapsulated in green case. Only used Toshiba/Hitachi transistors have green colour from Chinese sellers. All new 2SA968B were black. They are fake, I am sure. Finally I bought about 20 pairs of used 2SC2238-Y/2SA968B-Y. All were matched with success. Well I am sure they are genuine original Toshiba transistors. Similar situation concern Hitachi 2SK216/2SJ79. All new this type transistors offered on ebay and alibaba are in black cases. But they were encapsulated by Hitachi in black and green cases, so I hope the above ebay seller have original Hitachi transistors. I afraid if he will send me the same transistors as showed on ebay picture. I made special notice sending money that I interested in original black and greed transistors only. After I will receive them I let you know my opinion about the transistors (and the seller).
Click to expand...
with regards to your 2SA968B-Y, I have four "green" 968s but they are not "Y" but "O". Is there a difference?
 
#292
R-Cores might be something where the diyAudio store could serve as a purchase agent for a bulk order. Is anyone interested in a Google docs central location where over a few months, we could get a feel for interest and possible price breaks? A notice/link could be posted on several threads.

I did talk directly to the owner of Antek who said the problem was simply not enough requests from U.S customers to make it worth his time and investment.
 
#293
I bought the R-core trafos 120VA 2x30V in Selectronic. This is a distributor of electronic parts from France. They have a good prices. I paid 39,95EUR/1pc. + VAT but postal fee from France to Poland (inside Europe union) is high: 26,90EUR for parcel of 3,23kg weight.
Quality of the trafos looks good.
 
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