gates sta-level tips

hi, i'm trying to build a gates sta level clone, i found informations about transformers but nothing about the choke.. can someone give me help?
paolo

The choke just needs to be somewhere around 10 H at around 100 mA. Not that critical in terms of the sound.

-Dale

I believe Rob Finn made one a these dont think he would mind answering some questions,think he had a web page about it too, I made a BA6A similar vari mu job, Rob and others gave me sound advice pardon the pun.....good luck.


Cheers ....................Gary O.

thank you guys, this is my second varimu project, the first was an altec 436c that was completed successfully.. this should be a little more tricky but the schematic is very plain, trafo are available from sowter and i've found a 6386 at 25 ? wich i think is a good price.. i'll let you know how the project proceeds..


paolo

[quote author="pahstah"]i've found a 6386 at 25 ? wich i think is a good price.. i'll let you know how the project proceeds..


paolo[/quote]


Remember you cant just buy ANY 6383, the two triodes must be matched. This rules out >90% of the 6386s ever made. I think Manley sell suitable ones for around US$500.


M@

Im not as techy as most here but is there a way to add a pot to balance the 2 halfs of a 6386 if they didnt match ????

choke 10H at 100mA

The output stage has a balancing pot which to some extent balances what happens in the previous stages. I haven't found this to be a problem

yes you can trim them, but the 6386 still needs to have matched gain levels. I suguest looking on e-bay. There is a guy there selling lots of 5749's when wired in triode mode will be pretty damn close to a 6386. then you don't have try and match to triodes in a single bottle. Thats what is being used the the Glory Comp and what is used in the T-bar mod from M*nley.

my 2 cents

Wilebee

yes, it is best to have matched gain levels in the 6386, but in practice I have yet to find this a problem.

Even if you trim them there is little chance that they will be matched at all places on the curve anyway.

my 2 pence

Rob, you must have somehow managed to find only matched 6386s as the vast majority weve seen arent and thump like hell in circuit.


M

I'd try that cheap 6386 for starters.

Maybe I've just been lucky, but all 3 of the 6386's I've picked up for cheap ($30) have worked perfectly in a Collins, which is very similar to the Sta-level. The Collins has a balance pot but it has to be turned to either extreme to have a negative effect on the sound. I think these cuircuits are loose enough that it shouldn't be a problem unless your 6386 tests bad.

I've a pile of about a dozen used 6386's, and have only found thumping to be a problem with the ones that measure as obviously near-dead or severely different side-to-side. The chief thump culprit I've seen in circuits is too much low end getting through the side chain to the rectifier. Sta-level's don't let too much through, which is why they are as smooth as they are. A Collins 26U in comparison lets the whole frequency range into the sidechain since it is meant to limit all signal to the radio transmitter, and will thump more easily with heavy low end inputs. Change to lower value sidechain caps and the thump goes away. The Manley lets full low end into it's sidechain as well, thereby making tube selection vastly more critical.

hi everybody, i'm collecting components for sta level and i have another quetion: can i use 1/4 watt resistors?
and the meter is a microammeter? as in altec 436c?

thank you
paolo

hi everybody, i'm collecting components for sta level and i have another quetion: can i use 1/4 watt resistors?
and the meter is a microammeter? as in altec 436c?

thank you
paolo

hi everybody, i'm collecting components for sta level and i have another quetion: can i use 1/4 watt resistors?
and the meter is a microammeter? as in altec 436c?

thank you
paolo

hi everybody, i'm collecting components for sta level and i have another question: can i use 1/4 watt resistors?
and the meter is a microammeter? as in altec 436c?

thank you
paolo

hi everybody, i'm collecting components for sta level and i have another question: can i use 1/4 watt resistors?
and the meter is a microammeter? as in altec 436c?

thank you
paolo

it is an milliammeter,
As far as I can remember most res are 1/4w unless stated on diagram

thak you rob, i asked about resistors cause ive found in a scan of stalev manual that resisistors were 1/2w, but since that was really an unclear scan i had doubts...

paolo

I can't understand why you don't just use 1/2w because it's not like they cost any more.

For valve kit I normally use 1watt resistors, because if you point to point wire it is much easier, because they have stronger leads.