Now I get what you mean. That wasn't from a builder who had quads of several types and knew the preamp's sound for long. It was a hasty mix and match in a fresh build by enthusiasm. Not even in stereo. Hardly indicative let aside conclusive.
"Having disposable only one true Toshiba transistor, I do all test on one channel only."
"Having disposable only one true Toshiba transistor, I do all test on one channel only."
I ordered 2 new boards. The new BOM for DCB1 shows 2X15V for the transformer. Is 2X12V still acceptable?
Good deal here https://canada.newark.com/multicomp/mcta050-12/toroidal-transformer/dp/38K4881
Good deal here https://canada.newark.com/multicomp/mcta050-12/toroidal-transformer/dp/38K4881
I have made this years ago and now im wondering if i should change my noble potentiometer out with something better.
I have 2 options.
TKD 2CP-2511 with motor, so i can get a remote. Well i am a little lazy.
Or i have a Elma 2 pole 24 way switch lying that i could use as a stepped attenuator. Stepped attenuator is all new to me, but it could be a fun little projekt, but its probably going to be "low end" resistors. Not sure which one is a good buy.
But what would be best sounding?
I have 2 options.
TKD 2CP-2511 with motor, so i can get a remote. Well i am a little lazy.
Or i have a Elma 2 pole 24 way switch lying that i could use as a stepped attenuator. Stepped attenuator is all new to me, but it could be a fun little projekt, but its probably going to be "low end" resistors. Not sure which one is a good buy.
But what would be best sounding?
Forgive a johnny come lately (I just received the ten years after board) and a tube builder to boot, but, I've tried about every Pot and attenuator on the planet.
I hate the Alps Blue. Hot treble.
Alps Black even hotter but a better soundstage.
PEC KKA series are quite good but channel balance can be an issue.
The new Audio Note pot is very good, almost as good as the TKD at less than half the price. Unfortunately, it's only 100k.
Valab on Ebay sells a very good stepped attenuator but it's not wired with lugs or eyelets and soldering to the SMDs is a pain so order 2 :-}
There's also a ladder attenuator on ebay with eyelet's but the most recent one I ordered had connection issues.
For price and impedance matching to the DCB1 the best bet is PEC KKA2531S28, 25k; digikey part #KKA2531S28-ND
I hate the Alps Blue. Hot treble.
Alps Black even hotter but a better soundstage.
PEC KKA series are quite good but channel balance can be an issue.
The new Audio Note pot is very good, almost as good as the TKD at less than half the price. Unfortunately, it's only 100k.
Valab on Ebay sells a very good stepped attenuator but it's not wired with lugs or eyelets and soldering to the SMDs is a pain so order 2 :-}
There's also a ladder attenuator on ebay with eyelet's but the most recent one I ordered had connection issues.
For price and impedance matching to the DCB1 the best bet is PEC KKA2531S28, 25k; digikey part #KKA2531S28-ND
Just having a look through this and the build thread on Audio Circle I don't see a board that has TO Heat Sinks installed on the transistors, or eyelets for them on the Ten Years After board I just received.
Heat sinks are mentioned in numerous places, some with the chassis used as such. There are mentions of not needing heat sinks only if the current is "hot rodded".
TO's are on the BOM so what does one do?
Heat sinks are mentioned in numerous places, some with the chassis used as such. There are mentions of not needing heat sinks only if the current is "hot rodded".
TO's are on the BOM so what does one do?
If you stick to the build (don‘t hotrod), you can use the bottom-plate as heatsinks. Gives you more freedom in the placement of parts (toroid, „pot-bar“, etc).
(Master Salas probably will chime in with a more sensible answer [emoji6])
If running it near 200mA shunt reg PSU CCS bias with the four 18 Ohm setting resistors as recommended (9 Ohm value resulting per side because in parallel) it surely needs sinking aid. Not much, the chassis floor itself or medium sized chassis supported side sinks are enough. The big MOSFETs can run reliably long term alone up to about 60mA for the voltages involved in this circuit. The TO-247 MOSFET package doesn't need insulation grommets but still needs insulation pads.
I went by the bom—big fischer heatsinks and the TO-hs. Sorry, no pic yet, I‘m in a different place at the moment.
Here’s what I can show you, plus Salas‘ directions in the ff: https://www.diyaudio.com/forums/pass-labs/176723-mezmerize-dcb1-building-thread-218.html#post6069825
I‘ll be in my Atelier tomorrow, will post a foto then...
Well, I guess it’s my turn... I’ll be placing a parts order soon. I just read the entire thread. It will be a few months before I actually start smelling solder so I hope this thread is still alive when the time comes.
I’m really hoping I won’t have to bother poor old Mr. Salas but you never know.
I hope all of or at least some of the successful builders can help future builders like me so Mr.Salas can have time to create another fine piece of art.
Mr.Salas, thank you for being you! You are like a tree who bends low to offer fruit to small children. Thank you!
I’m really hoping I won’t have to bother poor old Mr. Salas but you never know.
I hope all of or at least some of the successful builders can help future builders like me so Mr.Salas can have time to create another fine piece of art.
Mr.Salas, thank you for being you! You are like a tree who bends low to offer fruit to small children. Thank you!