Gates STA-Level Recovery time MOD?

I´m working on a Gates STA-level and it´s in really good condition. However, for music recording work, I want to implement the so called recovery time MOD. I think it´s a dual pole switch for changing the recovery speed. I don´t have any other info other than what the original manual says...

From the original manual:

Recovery Speed: As supplied, STA-Level recovers 2/3 level in 7 seconds and 90% level in about 28 seconds.This is considered typical. However, a kit of small fixed resistors is supplied. If the operator feels this is too slow or too fast, he may, by changing two resistors, increase recovery to as fast as 2/3 level in 2 1/4 seconds and 90% level in 10 seconds, or as slow as 2/3 level in 11 1/4 seconds and 90% level in 45 seconds.

Click to expand...

And here is the schem:



So, I think that the resistors involved are R36 and R37. Can someone confirm it?

Does anyone knows what were the original values supplied by Gates in this fixed resistor kit mentioned in the manual?

Thanks for reading!

Hey there is a Sta-Level on ebay right now, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7351224543&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1
that shows a paper on top of the unit with time constant resistor values, the picture is ok, but maybe the seller would be kind enough to provide the info from it. hope this is helpful.

Yes, looks like this is exactly what I want. I tried the seller. Maybe he can send me a scanned copy or a better pic. It´s unreadable in the auction.

Thanks a lot!

I almost emailed the seller about it a little while back (the resistor list), not the first time that Sta-Level has been up. If you do get a better pic please pass it along.

It's not so hard to read...

Qty. 2: 1.5M

Qty. 2: 3.3M

Qty. 2: 4.7M

Qty. 2: 7.5M

Qty. 1: 15M

Qty. 1: 20M

Dave, you got good eyes. I really couldn´t read it.

Rob Flin sent me a complete paper. Here it is:




Looking at the schematic again, I guess I can´t just drop a switch in there for R36 and 37 because there is a DC path through R36. But I know people that did this mod. Maybe they switch with the unit turned off only??? At least it´s better than unsoldering and soldering resistors to change recovery time.

What do you think?

Just use a shorting switch. No problem...

I just used the 2 fastest settings on the 4 sta levels that I`ve built.
I don`t worry about not having much control on the recovery times, because the kind of job it gets used for I find doesn`t require that sort of scalpel like precision.

If I need more control I just patch in a different compressor.

rastafred or rob.could you be kind enough tell me what are the choke specs. henry and ohm .as i plan to build one soon....
thanks a lot.
audioforge

I think I used 10H at about 100mA.

If you look at the diagram after choke L1 it it says 300v 80mA, so 100mA gives a little headroom. The amount of Henries is not wildly critical if you uprate the caps C12a & C12b to say 47uF (be careful not to exceed the 5Y3 rating for input capacitance). Just make sure you have maybe at least 5H.

Its great there is another discussion about the Sta-level, things to consider while I'm soldering mine together.
:thumb:

Are you using 20uF cap after the power rectifier tube 5Y3?

In the 5Y3 datasheet it says that the maximum capacitance input of the filter should be 10uF, but it seems that gates used 20uF. As I´m recapping, I thought I should ask if your units came with a 10uF or 20uF cap.

Do you think a modern 22uF/450v cap could be a problem for this tube?

Mine has a 20uf

your talking about C12A and C12B right?

Ive used way more than a 10uf on a 5y3 with guitar amps and havent yet had a problem. Dont know about the 10 year life span of the tube, but havent had any issues yet.

dave

Hey what is connected to Pin 5 of tube XVI (6386)
Schematic says nothing..

Here might be some useful information for you rafafredd. This comes from a complete Sta-level manual (not one of those consumer pamphlets) dated 4/30/1956 from the Gates Radio Company.

All Measurements made with a Simpson "260' Test Meter
All Readings are made with respect to common "Buss" Ground
R1 - R27 -R38 Set at minimum (CCW)
S1 - "OFF" position and "AC" Disconnented
S2 - "Single" Position

TB1 (input terminal)
1- INF.
2- Short
3- INF.

XV1 (6386)
pin 1 - INF. (heater)
Pin 2 - 200
Pin 3 - 5 MEG
Pin 4 - 170K
Pin 5 - 65
Pin 6 - 170
Pin 7 - 5 Meg
Pin 8 - 200
Pin 9 - INF. (heater)

XV2 (12AT7)
pin 1 - 220K
Pin 2 - 150K
Pin 3 - 1.6K
Pin 4 - INF (heater)
Pin 5 - INF (heater)
Pin 6 - 220K
Pin 7 - 150
Pin 8 - 1.6K
Pin 9 - INF (heater)

XV3 (6V6)
pin 1 - Short
Pin 2 - INF (heater)
Pin 3 - 142
Pin 4 - 155K
Pin 5 - 160K
Pin 6 - 5 MEG
Pin 7 - INF (heater)
Pin 8 - 250

XV4 (6V6)
pin 1 - Short
Pin 2 - INF (heater)
Pin 3 - 142
Pin 4 - 155
Pin 5 - 160
Pin 6 - 155
Pin 7 - INF (heater)
Pin 8 - 250

XV5 (OB2)
pin 1 - NC (not connected)
Pin 2 - Short
Pin 3 - NC
Pin 4 - NC
Pin 5 - 95K
Pin 6 - NC
Pin 7 - NC

XV6 (6AL5)
pin 1 - 280K
Pin 2 - 5 MEG
Pin 3 - INF (heater)
Pin 4 - INF (heater)
Pin 5 - 280K
Pin 6 - NC
Pin 7 - 5 MEG

XV7 (5Y3)
pin 1 - NC
Pin 2 - 145K
Pin 3 - NC
Pin 4 - 180
Pin 5 - NC
Pin 6 - 180
Pin 7 - INF
Pin 8 - 145K

C12 (20-20)
A - 140K
B - 140K

C7 (15-15-10)
A - 160K
B - 142K
C - 155K

F1 (Fuse)
1 - INF
2 - INF

TB2 (output terminal)
4 - INF
5 - INF
6 - Short
7 - INF
8 - INF

EVERYTHING IN ohms

The manual is for a M-5167 Sta-Level.

I don't know how many versions Gates Made.. if they did make more than one

I had a Sat-Level on my bench a few months ago that had an attack and release mod in it. It worked decent enough, but there were settings that were too fast and it caused some strange thumps, etc. It is possible that it brought out a slight imbalance in the tubes. I ended up removing the 'fast' setting to fix it. As they are stock, they are really just a leveling amp - I could never hear any compression artifacts.

As I remember, R35 (56K following rectifier) was split into a 10K (or something) fixed resistor followed by a 50K pot to become "attack", and then R36 (4M7) was changed to a fixed 1M with a 1M or 2M pot in series with it as the "release" adjustment. There was a switch to change the C10 value as well to adjust attack/release characteristics. The problem surfaced when using something like a 0.01uF cap and the attack and release set to "fast" (min resistance). At these settings every now and then a kick drum would cause a big "whump". I think I have this mod documented if anyone is interested.

Tim

I would love to see the mod schematic

Yes, It would be great if you could post a schem for the mod...

Thanks!