[BUILD] STA LEVEL PCB OFFICIAL BUILD & HELP THREAD

[Le Roux]

Perfect!

Thanks so much

Almost finished first one.
I’ll post pics once completed

Cheers
Neil

 

[Kid Squid]

Hi Chaps,
Hope all is well !

Just got back into Sta-Land, been heavily involved with a project at work and its swallowed up pretty much all of my free time.
Great to see the various builds coming along  ;D

Had some bad news regarding my transformer contact at Avel, They closed down in January.
All of the winding machines etc have been shipped to the parent firm, but existing designs should still be available on request through Roshe Power UK. So if you need any more, get in touch with 'em.

Gutted.

Best
Steve

 

[Le Roux]

Finished both and they sound great!
I had to do the 20watt chassis mount resistor at R3 for both. One with a 1k ohm and other 500 ohm to get voltages within range.

Oh, and did a Upad along with the T-Pad attenuators

Thanks for the project, case and any help I received, even to those that posted great information in this thread!

Cheers

 

[Le Roux]

Front

 

[bernbrue]

They look gorgeous! Congratulations!
Bernd

 

[BramK]

Has anyone opened up an old Simpson Model 27 meter to replace the dial? Any advice on how to approach this safely? I hear one needs to be careful with any ferrous objects (including the screwdriver) when opening one up.

 

[IanB]

Hi guys.
Finally getting around to this project and getting all the stuff together.
I have a couple of questions and would appreciate your help!
Did anyone use Steve’s bypass switch? If so do you mind scrawling a pic pretty please? It’s kinda blowing my (albeit tiny) mind!
Also, this means I don’t need to use the relay board (as long as I can figure out the switch wiring). Correct?
Finally - has anyone tried/used the Hairball output attenuator? Should work pretty well shouldn’t it?
Thank you guys!

 

[Le Roux]

You will need that relay board
Simply use the two connectors on the end of the pot as an on/off switch going between rather grey or violet wire on the wiring diagram which powers up the relay board.
Wire up the deck poles to the board as per wiring diagram

Attached is how I did the U-pad for people’s references

I used the U-Pad reference from this Thread and wired Steve's pots the same way the 600 ohm T-pad is on the Capi-Gear site referencing the pcb
The U-Pad resistors were the same values that Hugo used, so I went with those.

 

[Le Roux]

Other t pad reference pic

 

[IanB]

Thank you sir but Man I’m confused.
So you’ve wired the output pot as a U Pad? The 600ohm CAPI should work well then do you think? (I’ve got a few of them for other builds - they’re pretty great!).
I thought Steve’s pull/switch input knob was a hard bypass? No?
I also thought the relay board was for bypassing the unit. So Steve’s pot still needs the relay board to work?
Sorry for being a *******. I’ve only wired simple guitar pots before.

 

[Le Roux]

Yes, the Capi t-pad will work.
Required due to the crazy amount of gain.

The relay board is the hard bypass and is used in conjunction with Steve’s pot

 

[IanB]

Excellent! Thank you so much!!
Ian

 

[Le Roux]

If you find it still has too much gain with the T-pad, you can add the U pad the same as I have it wired in the pic to the capi T-pad.
That output pot in my pic is actually the same as the capi one, just different lol

 

[IanB]

Your pic was perfect but it made my brainbox hurt! Haha!
Wow! So lotsa gain on offer. I’ll try the Bourns and hear what happens!
Thanks again for replying & helping! This thread was >120 days dormant till I woke it up!

 

[schrobbelbop]

Ah, allright, thanks!

I did exchange the output pot to a new stepped switch reading 1K, double checked all the wiring, resoldered the input put.

The unit works - on  one channel.

I made you guys a video:

http://we.tl/TVpoB5Rti5

You only hear one channel at once.

First, you will hear the left channel. This is the bad one. On 0:10 for example you can see and hear, how the compression bangs in with a THUMP, then only very slowly returns.

After that, i switched to the right side. This side sounds better and reacts very fast, off course depending on the setting.

I did switch back and forth the Input Pot, Recovery + Mode switch,  Input tranny and most of the tubes from the good and the bad channel, to rule them out as causes for the problem.

Did you find out what caused the thumping? i have the same issue's in my drip version...

 

[IanB]

Hey guys. Some more wisdom please!
I’m going to use the Hairball T Pad output attenuator with its little PCB. Do I bypass R25S, R26S, R28S, R29S, R30S & R40S? So just wire + & - from the output Tx to the Hairball T-Pad PCB +/- “in” and then wire +/- “out” to “AudioOut” on the Relay PCB?
I don’t think I need that Resistor network. The T Pad should be able to take the level to zero. Correct?
Thank you!

 

[SKJGProject]

will try to work on this in 2020....anyone wants to share his mouser cart/project?

 

[zero]

Hi people,

I´m having trouble with mu build,

I built it, worked fine but started to blow fuses.

Took it apart and got to find that the B+ voltage went up to 440V :-[

I had it at 290V but had to drop voltage at R3 with 3x 470ohm 25w resistors as per this post recommendations as i´m usin Don Audio trafo that outputs 330V but in my limited knowledge doesen´t seem like a great idea as it heats up like hell.

Also, only now, trying to understand whats going on and after reading the TL783 datasheet, got to see that it´s maximum  voltage is 125vdc and it´s regulating to 300vdc.

Another thing, why is the HT Trim optional and recommended to put a shunt in it´s place?


Any ideas on this?
Help please?

Thank you.
Cheers

 

[bernbrue]

Looks like a thermal shutdown. How did you cool the TL783?
Bernd

 

[zero]

Looks like a thermal shutdown. How did you cool the TL783?
Bernd

Hi Bernd,
With the heatsink from the boom.
Even cold it´s outputing 440V.