Who knows these two tube preamp boards ?

[as_audio]

Starting to clean up my mess I found two circuit boards of what seems to be tube preamps.
May be kits of some DIY project.

First one:

- 150 x 285 mm, red board of good quality
- two tubes 5814A similar to 12AU7, ECC82
- heavy regulation with semiconductors LM1086, IRF840 2x
- big Solen and Clarity caps

There is no indication of brand or manufacture.

Second one in post 2.

Thank you for help.

 

[as_audio]

Or this one ?

Now the second one:

- 136 x 151 mm board size, blue, gold plating
- two tubes 6922/ECC88
- balanced inputs, unbalanced outputs
- passive supply
- not sure two IRF9610 Mosfets are for plate supply

Some members of this forum will know more, thanks again.

 

[Tesla88]

I was lucky with the first one here :

Hi-End DAC tube output stage

 

[as_audio]

This applies to post 1 - how did you know ?

 

[Tesla88]

I just entered " LM1086 IRF840 ECC82 " in the search field in Google images

 

[as_audio]

Well, I did this also ! No result.
Google will tell different people different results.
However, I am amazed, thumbs up.

 

[Tesla88]

I found the second one on ebay - no schematic but you might ask to the seller

BAL/unbal Input TUBE Vorverstarker Stereo PCB! | eBay

 

[as_audio]

Excellent.

 

[as_audio]

Tesla88, see the second board has Tesla tubes ECC88 ?

 

[as_audio]

Bal/unbal input tube preamplifier stereo PCB Ebay 220844600656
Perhaps some member can help out with the schematic for the item in post 2 , thanks.

 

[Tesla88]

Did you ask seller ?

Btw if you have some spare time and a bit of patience it's not hard to draw a schematic doing a reverse engineering from that board, just few components...