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Maybe just post them to the thread... Still not sure what all the interest is in this, but I confess to not having built one. The SS Dynalo is a better amp from what I understand. Or the CFP2... Sent from my iPhone using Tapatalk

Yes, dropping R14/R29 drops the bias level. Sorry for any confusion in past posts.

You should be OK, assuming you are using the right adapters (don't use the SA1349/SC33xx adapters!). There aren't really any voltages present there that would damage the JFETs, unless the Gate is wired incorrectly.

I probably got it backwards as from what I recall, the 402R biased it hotter than the 422R did. IThe 15mA or so came after it was running for at least 30 mins, more like an hour. Putting the heatsinks on should drop it a bit (couldn't measure, but based on overall current draw of the amp). EDIT: just played around in a spice model, and lowering the LED resistors (R1, R3) biases things hotter.

Yeah, I also like that one a lot. Not quite up to your guys levels, but my wife got me this for Christmas...

Happy Merry Birthday!

Do you mean the ACN (Analog Crossover Network)? That was the only thing even close that I found there...

2SJ109BLs are a tough ask (for genuine ones). You could use singles (2SJ74 or Linear equivalents), or the Linear duals with some lead manipulation. Maybe: https://www.diyaudio.com/forums/swap-meet/320192-toshiba-2sj109bl.html This guy... maybe: https://www.ebay.com/itm/Matched-quad-of-2SK389BL-2SJ109BL-100-original-and-genuine-Toshiba-015-idss9-9/282424664232?epid=593519663&hash=item41c1d260a8:g:2-oAAOSwuxFYtUc~:rk:3:pf:1&frcectupt=true

Happy Birthday Ken!!!

Tangent has an article on his site ( http:// tangentsoft.net/audio ) on building a load box. He used 33 and 330 ohms, but did mention 120 as a third option. Sent from my iPhone using Tapatalk

What they said regarding community participation. As for adding a headphone jack, you could simply wire a pair of RCA plugs to a jack (1/4” TRS). The L+ would go to the Tip contact of the jack, the R+ to the Ring contact, and the Gnd to the Sleeve. If you have room on the faceplate for the jack, wiring it internally would be a nice plus. Not sure how good it would sound, so going the cable route would probably be advised until you determine that. I would also measure the DC offset (L+ to Gnd, R+ to Gnd) before plugging any phones in. 10% distortion at 1000Hz? That is pretty awful if accurate. Sent from my iPhone using Tapatalk

It appears that the 750R / 511R voltage divider feeding the opamp is what sets the gain, but I didn’t find a formula for calculating the output voltage. One guy dropped his to 19V by paralleling a 2k resistor with the 511R. https://www.diyaudio.com/forums/headphone-systems/109618-krell-ksa5-10.html#post5190186 Sent from my iPhone using Tapatalk

Why? 1 to 2 volts is a pretty minimal change. Sent from my iPhone using Tapatalk

Yes Sent from my iPhone using Tapatalk

R52/R53 and R56/R57 (200K/10K) dynahibalbjt.pdf

These are the boards; I had seeed run 10 of them. Guess I'll have to build one up and see if it works... The board is a bit larger at 116 x 107mm, so new build only. Mounting holes are inset 5mm (x,y).

I think this is right (and already had some run), but if someone wouldn't mind checking the schematic, particularly around the rectifiers, I'd appreciate it. I had corresponded with ang728 back when he did a multi-output version of the GRLV, and he sent me his layout files. I made some changes to these around: Added dual rectifier banks, supporting TO220 packages so I could use the SiC schottkys as Kevin did on his 35mm cap board Supports up to 35mm main filter caps Outputs will take either 5.08mm LS or 2.54mm LS connectors (i.e. Molex SPOX or KK) Added positions for xfrmr secondary snubbers Removed the caps across the rectifier diodes as they aren't a real snubber and don't do anything useful

Waiting for CSO... Wagner- Overture to Rienzi R. Strauss- Four Last Songs Nielsen- Symphony No. 4 Sent from my iPhone using Tapatalk

Happy Birthday Todd!!! Sent from my iPhone using Tapatalk

I think IIRC that stripe (+?) o the tantalum goes towards the back of the board. Also, I wouldn’t populate the 0 ohm jumpers until you have tested and adjusted the amp. Sent from my iPhone using Tapatalk

^ This. RIP 41.

You didn’t look hard enough Looking at the amp from the front, the channel layout is L- L+ R- R + The two pots by the LEDs balance the +/- for that respective channel. The other 4 pots adjust the channel closest to it. There is some cross action with the other phase but not a lot. Normally you don’t need to do much with these. You can also get yourself in trouble with these if you go too far. If that happens, reset to midpoint (using a DMM on ohms) and start over. Sent from my iPhone using Tapatalk

Well it raises the input impedance for starters. I think Kevin told me you could go 10x on the gain resistor combo and use a 25k or 50k pot if you wanted to. I always left things stock on the ones I built so the users could go to BJT input if they wanted to. I think the JFETs sound a bit better, but I could be delusional... Sent from my iPhone using Tapatalk

I’m not sure if it increases or not. Since everything in a Dynalo mini is integrated. I would think a grounding issue is unlikely unless maybe something to do with the house wiring. And these aren’t prone to oscillation from what I’ve seen. DynaFET is another story... Sent from my iPhone using Tapatalk

^ search back in this thread for some suggestions. Should be easier with the 2oz copper boards than it was with the 3oz from the previous GB (who DID suggest going 3 oz... )? My personal suggestion would be stencil, solder paste and an oven. On another subject: One of the amp recipients that I did a build for has had some problems with his amp since it was delivered on Friday. Here is what he told me: BAL source, SE headphones = slight hiss in left channel BAL source, BAL headphones = no issues SE source, SE headphones = large hiss in left channel SE source, BAL headphones = no hiss in left channel, but turning the pot creates a lot of static So far the suggestions I have made were swap the THAT chips (this is one who didn't opt for the FAR superior JFETs check the source in SE mode for DC offset, and try grounding the pot case. When testing these, I did verify continuity on all of the case panels, at least on the first 2 I built. I never had to do anything as the screws seemed to make good contact. The eject tabs on all of the XLR connectors had continuity to ground as well. Any thoughts? Thanks in advance!