Sherlock Level-Loc Clone Troubleshooting

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Greg

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Joined
Jun 7, 2004
Messages
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Location
New Orleans, LA
I have a Sherlock Level-Loc Clone that I finished building some time ago. I finally got it on my test bench and it seems that I'm getting output from the aux output, but not the transformer output. I'm having a tough time troubleshooting this circuit b/c I don't have a schematic, or even a PCB layout. A PCB layout would be nice so I can check my resistor values again. At the moment, I'd have to lift the resistor to see which resistor I'm checking. See my point? Does anyone have any of this info? It wasn't included with the clone documentation.
 
i just took a look at my kit instructions and no pcb layout or schematic here either, though there is a credit for pcb design by 'harry'. perhaps drew at drewtronics can put you in touch w him. there's bound to be a layout somewhere..
i'd scan the pcb for you but mine's built already.

note to self, scan pcb's before assembly when no layout doc is present.

-scott
 
I received my level loc pcbs today, I'll buy all parts next week
and then put it together...

did you get the original transistors: 2N5089, TIS93 , 2N5458
or substitutes??
transformers ??

mat
 
can anyone with a working unit post voltages on the transistors and fets? Ive tried to contact drew about this but had no luck. I cant get mine to work properly at all and it sounds to me like a bias problem, but Im not too sure where the voltages are supposed to sit in the first place...

dave
 
[quote author="matthias"]did you get the original transistors: 2N5089, TIS93 , 2N5458
or substitutes??
transformers ??[/quote]

I ordered a complete kit from Drew, which included the original transistors and a pair of trannies (don't know what kind they are though). Nothing that expensive that's for sure. I ordered it probably 6 months or so ago. I put the PCBs together then moved on to an SSL and some other balancing circuits and things. I'm finally getting back the clone now. I got the PCB layout from Rob so I'm going to go back and check resistor values and double check to see if I made any soldering mistakes. I already checked my caps and transistors, and they are correct. It's just tough b/c I don't have schematic... if I did I could find where the signal is dying.
 
[quote author="soundguy"]can anyone with a working unit post voltages on the transistors and fets? Ive tried to contact drew about this but had no luck. I cant get mine to work properly at all and it sounds to me like a bias problem, but Im not too sure where the voltages are supposed to sit in the first place...

dave[/quote]

Voltages at the transistors would be most helpful !!!
 
[quote author="Rob Flinn"]I must say that it would have been useful if Drew had provided a copy of the circuit diagram. I suspect that it is not absolutely identical to the shure.[/quote]

Drew will email you a schematic if you ask him. I found it helpful when trying to eliminate the hum I was getting on the aux out.

Leigh
 
@ rob what's the correct way to stuff Q6 and Q7 ??
like the drilling holes or in the direction of the print??

I can`t remember for sure off hand, but I think it was the direction of the print. I seem to remember that it might have mentioned this in the construction manual. I can take the lid off mine tomorrow evening if you need to know for sure.
 
In case anyone is still intrested in voltages...
I built a two channel version, and both channels seem to behave about the same. So, I just measured voltages on one channel.

BTW - I get very little 'effect' out of the main outputs, but the aux outputs sound good and whacky. So, I installed and wired a switch between the outputs and the output transformer to select either the main or aux output for the OT.

My power supply measures 12.9V.

Q1
e 3.78
b 3.85
c 7.31

Q2
e 3.20
b 3.79
c 7.30

Q3
e ~0
b 0.68
c 3.17

Q4
e ~0
b 0.82
c 4.14

Q5
e 2.59
b 3.13
c 9.20

Q6
e 11.78
b 11.71
c 3.00

Q7
e 11.78
b 11.71
c 3.05

Q8
e 5.60
b 6.00
c 9.21

Q9
d 7.45
s 7.42
g 2.74

Hope that's helpful.

~ Charlie
 
moos - that's the problem I'm having. On the scope, my aux output seems to behave properly. It responds to the distance and level controls, but my main out is crap. I'm going to check my voltages against yours. Thanks.
 
There are a few sherlock threads over at TapeOp. May be some info about getting effect out of the main output. When I get a chance, I'll probably go read those threads again, too.

Drew commented that it acts weird/unuseable without the transformers, but that hasn't been my experience. I installed closed circuit 1/4" jacks for both the inputs and oputputs on mine that bypass the trafo when used.

~ Charlie
 

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