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Would it be a better idea to use the LSK489 (and LSJ689 for those needing 2SJ109)? And BTW, does anyone actually have the LSJ689 in stock?

Here is an updated spice file per Kevin's latest schematic (pls check). Still shows -51mV without the opamp. I guess the current mirrors purpose is just to take the servo out of the audio signal path, and not about offset without the servo? CFP2 1.10.zip

Those were dual BJTs, not JFETs, that Justin bought. They are the dual version of the 2SA970/2SC2240. Sent from my iPhone using Tapatalk

1. I have BOMs for both and the GRLV as well at home and can post or send tonight 2. Covered. My BOM has a “calculator” for this built in 3. Yes, you can use J74/K170 or equivalents. C-> D, B -> G, E -> S. Will plug right into the dip14 socket if you wish. 4. Maybe regarding the full vs. the mini. The mini uses the same devices, but the PSU is done using Meanwell AC/DC bricks 5. I am thinking about selling the mini boards and pots that I have (2). As for versions, the last GB earlier this year run by sbeylo would give you a handle on board versions. The MPSW06/56 thru hole devices are discontinued and not generally available so SMT with the PZTA devices would be the way to go. Both are setup to use the THAT340 for input. Sent from my iPhone using Tapatalk

Looks like you have the servo input going into the noninverting pin of the opamp? Is that right? Sent from my iPhone using Tapatalk

A 2x30Vac SumR is what I am using on mine. The Antek transformers seem to work well also, and much cheaper. Sent from my iPhone using Tapatalk You can do anything you want Whether it is a good idea or not is another matter. I know I asked Kevin a number of pages ago about using ceramics here and he said he couldn’t guarantee that it would meet the noise specs that he had measured. I would suspect electrolytic would have pretty abysmal performance here. Much higher ESR and leakage I would think. Sent from my iPhone using Tapatalk

Here's a revised ltspice model with the revisions made (I think, someone check this as it was done vs. the gerber file). The current mirrors get the offset down to ~10mV without the servo opamp connected. CFP2 v1.10.zip

Yes. Dale RN60s are military rated, and will handle twice the power that they are rated for.

I know the Salas stuff is well thought of on diyaudio. Normally a balanced Dynahi would use two GRLVs. I don’t think Kevin is a proponent of shunt regulators but I’ll let him weigh in. I am planning on building Salas’ Simplistic phono stage but was going to use a GRLV plus PSU (or maybe dual mono GRLV plusses) for this instead of the included Salas shunt. I did my own board layout with the phono only. The GRLV is very low noise. Sent from my iPhone using Tapatalk

Wasn’t quite sure where to put this so... Ran across a thread on diyaudio for an all tube I/v stage for an ESS9038. I haven’t looked at the chip, but I thought most of the ESS dacs were either v out or could be configured for either? At any rate, I would suspect this is good in a not good way Pure Tube i/V for ES9038PRO-9028, 9018, AKM... http://www.diyaudio.com/forums/showthread.php?p=5259820 Sent from my iPhone using Tapatalk

Happy birthday Gene! Sent from my iPhone using Tapatalk

Yes

Damn! RIP Charles! Sent from my iPhone using Tapatalk

That was quick Kevin Sent from my iPhone using Tapatalk

I had just run across them on diyaudio and hadn’t looked at them closely. Sent from my iPhone using Tapatalk

JFETs... anyone look at ZVP3310 and ZVN3310 as possible J74/K170 replacements?

B grade if going with Linear Systems. Most of the Toshibas used were BL grade. And yes you might be ahead to just use the current boards rather than hunting the stuff down for these. Sent from my iPhone using Tapatalk

Agree with sbeylo. The gain resistors in your silk above are the 200k/10k and cap next to them. Some of the sand shown could be problematic: 2sa1145/2sc2705 2sa1358/2sc3421 2sa1349/2sc3381 Sent from my iPhone using Tapatalk

I don’t have the schematic handy, but will try to answer what I can 11 is the standard gain. Without the schematic, I can’t tell you which resistors though Use 1.7V unless you feel like calculating resistor values to arrive at the design CCS currents using something else That should be fine. Use something that fits the board Without the schematic, hard to say. If that shows the MPSWs you showed above, that could be a problem. Arrow may still have some. The nearest equivalent is the PZTA06/56, but those are surface mount. Also, I would assume that Kevin was using something more like MJE or MJF15030/15031 for the output devices? The 7815/7815 are there so you don’t have to use OPA445 for the servo opamp. If you omit them, you’ll need an opamp that can handle your +/- rail voltage. Also, I wasn’t sure if the lil knight boards were the Super Symmetry? Sent from my iPhone using Tapatalk

Happy Birthday! Sent from my iPhone using Tapatalk

Changed out to the 10K TKD from my ss dynalo. Huge difference (for the better). Will need to do some more listening and comparing to the Dynafet.

Nm on question regarding the rotary switch. What kind of beast resides in there? And how are you actually doing the gain switching (and rumble filter)? Relays?

The one I used was 81-RDEC71E476MWK1H3B. From the spice model I built, I only see 5Vdc across this cap. It isn't marked polarized on the board, so I used ceramic instead of tantalum here. I don't think I ever saw a BOM here, so don't know what Kevin had in mind. From the silk markings, it would seem ceramic.

Yes, the 1 ohms are wirewound, from this post. I was thinking about using Mills MRA5s here.

Looks nice Marc! I might have not spelled Phonograph out (Phono), but otherwise. As for the knob and its 4 positions, not sure how you are doing that with a knob? How do you select MC + rumble on for example? The knob with a dot might look better than the line.