Pars

Speaking of using a GRLV for higher voltages, if I wanted to do somewhere in the range of 40-50Vdc, where would I need to go for voltage ratings with the various caps, particularly the tants? 32Vac secondaries. Thinking that one of these may be lower noise than the raw PSU/shunt setup on a Salas folded phono stage. EDIT: more like 35V. Also, the stock R7/R10 are 1.5K. I noted Kevin saying he went back to 2K precision resistors here for his +/- 20V. 2K would make getting the 35V easier (2K / 4.99K) Sent from my iPhone using Tapatalk

Neat Marc... I like how you used the SIP pins on that. Resistor leads into them? Creative...

take a look around this post

Any problem with using something other than the OPA134 for this? I normally use TL071/081 or the dual for servos. This isn't exactly a servo, and I thought I had noted someone (KG) advising OPA445 if doing higher voltage on the GRLV. Sent from my iPhone using Tapatalk

Very nice builds as well! What are the RCA connectors used on the preamp? Sent from my iPhone using Tapatalk

Happy Birthday!

Happy Birthday!

Happy Birthday Peter!

Very nice Marc!

87 of Robin Williams' bikes on auction (for charity): https://paddle8.com/auction/robin-williams/

Very nice! Any impressions on the phono preamp? Nice Marc! What series/manuf. are those connectors you are using? Hirose? Looking for 5.08mm pitch alternatives to the Molex SPOX that I use some.

Black as well, and showed these to my wife, who also agreed with this.

A phono cartridge is essentially balanced, so all separate wires from the headshell in. From what I recall, the two - signals are tied together in the turntable itself, so I think that undoing that and bringing them out somehow is all you need to do. Been quite awhile, and I've never rewired one.

Happy birthday Vicki!

Thanks Marc... I'll stick with what I have in there.

Yes, looking at the schematic, I would agree that even 20V would probably be OK. I'm using 35V for the 47uf parts in mine, and 25V for the 10uf currently, but that is just what I either had or sourced.

C7, C8, C9, C13 for the 47uf C3, C16 for the 10uf Assume a supply setup for +/-20V output, 2x23VAC input

Just an fyi, but the Excel BOM that I have has 25V tantalum caps, while Kevin stated 35V in this post: Note the part number provided above is actually a 20V part. Correct part numbers would be something like 581-TAP476K035CCS and 581-TAP106M035CCS for the 47/10uf parts respectively. Sorry, just getting an order together for the remaining parts to finish one of mine (v.42 or goldenreference4) boards. I haven't done a spice model or analysis to see what you really might need here, and I assume a number of these have been built with no problem according to the spreadsheet I had (which I can't find here on HC anymore).

Paid. Thanks!

If you go back a few pages, I posted something about some that I have marked Burans or something like that:

Agreed... subscribed.

Kerry, What is your impression of the Alpha pot since using it? Taking a quick look I didn't see anyway to get the TKD 601 and the Alpha to play nice together on the same board. If it wasn't for that damn tap or the way they did the pin order on it...

Yep, same here. Can edit f and g, but not h. Put me down for 3 of the all 3 pcbs (column h)

Kevin's formula is more accurately shown as ((R8 + R7) / R7) x 10

The potentiometers are continuously variable pots, whereas the attenuators are stepped attenuators and made up of fixed resistors, with a fixed number of steps, so a fixed jump between steps (2dB on many of them). Other examples of stepped attenuators would be Dact, Goldmund, etc. These probably track better, but the fixed number of steps could be a problem depending upon the volumes selected, and so on.