Well, yeah, I've thought about moving the output devices to a big heatsink... as a matter of fact I got a big one, about 9" by 10", right on the shelf.
But, that would be too easy. I did try triple stacking the heatsinks... it does work, but it does get a bit too funky looking...
Anyhow, I'm on the way to the hardware store to get more parts.. so cut, saw, drill, paint, bolt, glue, etc... I mean, a big heat sink is soo obvious. This, after all, is an AMP IN SEARCH OF A HEAT SINK. In fact, I was talking to my wife about it... looking at those big amps on the rack and thinking that perhaps Nelson gave us an amp that really should be sitting in a 4U chassis.
But, that would be too easy. I did try triple stacking the heatsinks... it does work, but it does get a bit too funky looking...
Anyhow, I'm on the way to the hardware store to get more parts.. so cut, saw, drill, paint, bolt, glue, etc... I mean, a big heat sink is soo obvious. This, after all, is an AMP IN SEARCH OF A HEAT SINK. In fact, I was talking to my wife about it... looking at those big amps on the rack and thinking that perhaps Nelson gave us an amp that really should be sitting in a 4U chassis.
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That's the first time I've seen 15-30 ampere screw terminals used as signal input connectors on an audio power amplifier.
Math note: (3Vrms input amplitude) / (10Kohms input impedance) = 0.3 milliamperes = 0.0003 amperes.
Math note: (3Vrms input amplitude) / (10Kohms input impedance) = 0.3 milliamperes = 0.0003 amperes.
Robustness...If something has the potential to break, I'm certainly the one that will break it. Also makes it a lot easier to swap boards in/out on an open chassis
ANY connector makes it a lot easier to swap boards in/out of an open chassis.
I used Euroblox screw-cage connectors plus Ferrules on the swappable boards of the Ship Of Theseus power amp; they worked great.
I used Euroblox screw-cage connectors plus Ferrules on the swappable boards of the Ship Of Theseus power amp; they worked great.
got a chance to listen to NP's BAF talk regarding Zenductor 2, I'm fairly certain we can use the JT-123 FLPCH and get a bit of a perfromance gain. I attached part of my PCB schematic, the JT-123 pinout, and ZENDUCTOR 2 scheme.... just chekcing to see if my transformer connections are correct...?
Attachments
Is this the same transformer as the Cinemag mentioned in Nelson's talk (the one he used in his Zenductor 2 + 100's of JFETs version)?
Sorry, you already answered that in post #114. So 50% Nickel is enough, no point going for the 80% version of either the CMOQ-4 or the JT-123?
Ultimately that’s a matter of taste. Higher nickel isn’t necessarily “better”.
In this application I’d go for 50% or standard, and ultimately I’d just buy what was in stock when I ordered.
In this application I’d go for 50% or standard, and ultimately I’d just buy what was in stock when I ordered.
I guess the eight components, vs two is to show off
Some people do a beautiful job, they look like 19 year old soldiers right out of boot camp.. all straight, in a row.
Then you gots Yours Truly. Mine look like a bunch of 58 year old sailors coming back to the ship after a weekend at Misss Wanda's House of Pleasures and Rum Emporium.
Sure, mine work too, a classic example of function over form... but, but....
`8 instead of 2...'?
Not sure if you are referring to the input jfets, but if so the substitution of 8 instead of two is for cost.
J113s are cheeeap, whereas 2sk170/LSK170 are very much not. Do some shopping. The J113 is not as `good' as the Toshiba/Linear Systems parts, but paralleling four pairs minimises the performance impact of the substitution.
Not sure if you are referring to the input jfets, but if so the substitution of 8 instead of two is for cost.
J113s are cheeeap, whereas 2sk170/LSK170 are very much not. Do some shopping. The J113 is not as `good' as the Toshiba/Linear Systems parts, but paralleling four pairs minimises the performance impact of the substitution.
A Zenductor2 that went to the gym and took its protein pills. Passed the smoke test, have't listened yet, letting it bake for a bit.
🙂
800VA/20V
26VDC loaded
1A (for testing)
JT-123-FLPCH transformer
193V inductor
600,000uF
2.2 mH PS inductor (10ga)
arduino style soft start
enjoy,
John
🙂
800VA/20V
26VDC loaded
1A (for testing)
JT-123-FLPCH transformer
193V inductor
600,000uF
2.2 mH PS inductor (10ga)
arduino style soft start
enjoy,
John
Attachments
Well, a little birdy sent me a box and we now have the Zenductor 2 running on 2S of 2S1P 5.2Ah packs at 16V at full charge, I’ve run the inductor voltage between 1.2 and 1.5v, and because the lipo discharge rate is so linear it doesn’t change much during listening of about 2 hours of battery run time. The battery power improves an already amazing amp when powered by the 16v bricks.
Characteristically, the lipo power delivers some incredible depth and width to the sound stage, with elements appearing in their own space as if all of the elements are on floating shelfs, being stable, deep, and very separate from the others. Musical elements are just vivid and large with this amp. The batteries just really exploit the strengths of the design and take it beyond. It’s a very enjoyable amp. The bass extension is jaw dropping on battery power, just as it is with the mini. The bricks cannot even come close to the lower octave power and the smoothness on top.
Thank you to Michael R, 6L6, Vincent and of course Papa for removing parts…..it’s a great achievement and gift to the community. I wish everyone could hear this in my listening room. I’ve been building tube and SS for a long time and this one is a masterpiece.
Loudspeaker: Martin Logan Montis
Preamp: Schiit Kara.
DACs: various DIY affairs: TDA1541A hybrid SS and 5687 I/V, Sabre 9018, Grounded grid 12Au7 output.
Amplifier compared to: DIY FW designs, XA25, Hypex Nilai.
Cheers,
Greg
Characteristically, the lipo power delivers some incredible depth and width to the sound stage, with elements appearing in their own space as if all of the elements are on floating shelfs, being stable, deep, and very separate from the others. Musical elements are just vivid and large with this amp. The batteries just really exploit the strengths of the design and take it beyond. It’s a very enjoyable amp. The bass extension is jaw dropping on battery power, just as it is with the mini. The bricks cannot even come close to the lower octave power and the smoothness on top.
Thank you to Michael R, 6L6, Vincent and of course Papa for removing parts…..it’s a great achievement and gift to the community. I wish everyone could hear this in my listening room. I’ve been building tube and SS for a long time and this one is a masterpiece.
Loudspeaker: Martin Logan Montis
Preamp: Schiit Kara.
DACs: various DIY affairs: TDA1541A hybrid SS and 5687 I/V, Sabre 9018, Grounded grid 12Au7 output.
Amplifier compared to: DIY FW designs, XA25, Hypex Nilai.
Cheers,
Greg
Attachments
I don’t have a part number but any 4S lipo of at least 2.0A or larger will do to power one amp for about 45min. I just happen to have these large 5.2A 2S packs that I use in series. Lots of affordable 4S lipos available on Amazon or the retailer of your choice.
I have tons of lipos and just relegate old packs for audio use.
I have tons of lipos and just relegate old packs for audio use.