GB for Salas Folded Simplistic Phono PCB

[Tea-Bag]

I have three more kits listed on Reverb, after that I will be out of stock until we get a general load of boards in from another GB, and also will need to raise prices a bit to cover inflationary cost of the parts I will have then run out of.

 

[Russellc]

This thing is a bargain at twice the price!

Russellc

 

[Tea-Bag]

GB for the boards and kits is now open. Link is in my signature, not visible in mobile. Message if you need me to manually add you.

 

[mk15]

Hello Tea,

I added my name in the spreadsheet for USFB PCB board and 2SK369 guad set. Can you see from your end ?
Also approximately how soon can the order be materialized ?

Thanks, Michael

 

[Tea-Bag]

Yes, looks good.

 

[hartbigsky]

Is there an updated list of the kits parts for this GB or are the BOM from the build guide still applicable as I see 2013 on it? I mainly am interested in the boards and the semiconductors that need test matching. Capacitors, resistors, terminals, plugs, etc. I like to pick myself within build guidelines. Which kits would you say are best for this. Thank you for help!

best regards,
Steve

 

[Tea-Bag]

Here is the BOM for the boards for the kits I use with them.
https://docs.google.com/spreadsheets/d/1L_ro2avLFSxt6D0jxuo6os9bY0fuLfhX1kVpBSPFMbo/edit#gid=0

Here is a somewhat basic build guide for new board.
https://docs.google.com/document/d/1ip_eB3CbCMnZqCa7Nrlpsx4D9TfRMBJnN2GqJsKhqFE/edit

I think if you are interested in your own parts, this will be helpful for values and sizing requirements anyways.

 

[cumbb]

Salas RIAA is, may be, the best JFet-phono-amp!
Do not throw away the feasible best sound by, for example, circuit board construction.
And: trimmers usually sound better than resistors.
Use better capacitors than you see here. But these FMDs also sound quite good: just a bit more grainy, coarser than the best others. Use as small as possible: mica or polyester. NO WIMA MKPs or other fat gimmicks.

 

[hartbigsky]

Hi Tea-Bag,
One last question for purchase. You have matched pairs and quads 2sk369bl's. From build bom that is 2 per channel if I understand correctly. Is there a reason to NOT have all 4 matched as a quad vs 2 pairs matched? Thanks

regards,
Steve

 

[pchw]

Hi Steve,

The answer is in the build guide notes section (below). It depends on how much gain that you need (or the type of cartridge that you have).





Gain. With Q1 and Q2 populated expect 62-63dB. Its OK for 0.2mV-0.4mV MC cartridges.
For 0.5mV+ MC cartridge and enough amplification in your control preamp or when having a medium MC 0.8mV-1mV, don't populate Q2,R3, use 2.2K 2W R13 for 56-57dB. Q1 IDSS and R2 as in the mentioned table. By trimming R8 when with FFT test gear you may match the channels better.
For high MC cartridge 2-2.5mV don't populate Q2,R3, use 68R R2 and 5.6K 1W R13 for 43dB gain. Choose Q1 between channels from a 10.5-12.5mA range at 5% IDSS pair tolerance.
For circa 5mV MM cartridge don't populate Q2,R3, use 91R R2, 5.6K 1W R13, 1.8K R4, for 40dB gain and proper overload margin. Use 100nF C3 only value when with MM.
Choose Q1 between channels from a 10.5-12.5mA range at 5% IDSS pair tolerance.



Cheers,

-fred-

 

[Tea-Bag]

The UFSP version has switches to move from pair to quad mode, and to add in multiple resistors depending on gain R13-R16 bank, leaving one on at a time. It is not really on the fly stuff, the device will have to be set again to get the VR for it.
This is discussed at the tail end of the build guide in a screenshot from Salas.

https://docs.google.com/document/d/1ip_eB3CbCMnZqCa7Nrlpsx4D9TfRMBJnN2GqJsKhqFE/edit

 

[hartbigsky]

So today I am using a Sumiko Pearl MM but that is not permanent as I still have to "get to" my ideal turntable which I don't know what that will be. I will probably have to start with a MM cartridge and save for a really good MC in time even then, so it sounds like I can have the ability to "grow" into a higher quality setup from where I am today, sounds perfect for me. I am building a new PassDiy B1 preamp now and also will soon have Korg B1 ready also have a Salas DCB I have waiting in the wings to build. These all pair with SET tube amps so I just have to find my preamp gains to setup phono boards if I am understanding correctly. Thanks for the information. I just need one each of quad 2sk239 and also 2sk170 kits on the GB spreadsheet? Thanks for the help everyone.

best regards,
Steve

 

[pchw]

I bought a matched 2sk369 from TB. Whoever needs such can ping me as I don't have MC cartridge and don't plan to buy one. LOL, it was simply a case of buy first and read the document later 🙂

-Fred-

 

[Tea-Bag]

If you order 2SK170BL triple pair and 2SK360BL quad with set of boards, it is all you need. I don't sell extra to preserve stock.

 

[hartbigsky]

If you want full range of cartridge selections do you order matched pair and matched quad or just quad needed? I marked both possibly an error.

Steve

 

[Tea-Bag]

If you want full range of cartridge selections do you order matched pair and matched quad or just quad needed? I marked both possibly an error.

Steve

If your not sure what cart will be paired with it, or want to change, the quad gives you the most options.
With that said, you can get 56-57db with just a pair.
With a quad , you can just use the DIP switches to turn off a pair.

 

[hartbigsky]

So I guess I can take pair off of spreadsheet as quad will cover MM nd MC options. Thanks!
Steve

 

[hartbigsky]

Hi Tea-Bag, I also signed up for an L-adapter w/parts for another project along with phono stuff does that need to wait for 2/27 phono GB or is it available now? Would like to get new PS into CD player before I start phono build. Thanks!
best regards,
Steve

 

[nkostop]

Hello, I would like to build the UFSP, I see that the group buy is closed, I checked on Reverb shop and see that there are 2sk369 pairs and the minikit. Where i can find the 2sk170? do I need something else from the reverb shop? Thanks in advance for your help!

 

[Tea-Bag]

I would never sell the 2SK170BL triple pairs solo on Reverb, they would be gobbled up by people not using the UFSP. They are only sold with UFSP kit when buying direct.