Salas hotrodded blue DCB1 build - Page 172 - diyAudio
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Old 7th March 2012, 12:39 AM   #1711
CR500 is offline CR500  United States
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Good point about trying the two values with less expensive pots. I'll give it a shot next week when I'm back home.
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Old 15th March 2012, 09:18 PM   #1712
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Hello,

I can't get rid of the feeling that something is wrong with my DCB1. It seems I've been here before: lack of articulation in rhythm, weak slam and bass. It's almost like somebody would play the drums with cotton buds.

I had this some time ago, but then eagle eye Salas has spotted my amateur grounding technique and made me a happy man.

It came back three weeks ago. Then I've spotted rca grounding wire badly soldered and voila back too good again. Then I had to change rca sockets because one was damaged. Everything seemed fine, until two weeks ago something went wrong again and again.

I've been searching for the problem for two weeks to no avail. Looks like checked all connections, solderings, cables...

So i've decided to record straight a sample straight from dcb1 output to computer (audacity software). Source is Rega3 with Goldring 1012gx and Graham slee phono.

Could somebody please listen to it on their own systems or headphones to tell me if overall balance is ok?

Maybe it's not DCB1 related problem at all. Maybe it's amp, speakers or room problem...

I can provide photos and measurements if anybody have a clue where to start looking...

Here's the link to the sample:

http://wtrns.fr/rkUS4DkZ4BJOv4
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Old 15th March 2012, 09:26 PM   #1713
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Quote:
Originally Posted by Siberia View Post
I can't get rid of the feeling that something is wrong with my DCB1. It seems I've been here before: lack of articulation in rhythm, weak slam and bass. It's almost like somebody would play the drums with cotton buds.
Did you checked transformer primary wiring?

Some time ago I've had a similar problem and it was caused by a bad contact between AC power cord and transformer primary.
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Old 15th March 2012, 09:27 PM   #1714
Salas is online now Salas  Greece
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Is the TT spinning well? Check with strobo.
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Old 15th March 2012, 09:43 PM   #1715
Siberia is offline Siberia  Lithuania
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Primary wirings seem fine. My Tx is in a separate box running quite a long cord to dcb1 one box. Maybe I should try Tx wires direct to buffer..

Salas, I don't have a strobo handy. Is there any indication it's running off speed? The problem persists with all sources, be it a cd or a pc.
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Old 15th March 2012, 10:14 PM   #1716
Salas is online now Salas  Greece
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Heard something like instability but if its on all sources, then it does not targeting the TT. Just because its mechanical it could have periodic issues was my first thought as you said good sonic comes and goes out of the blue over the weeks. Get your AC wiring to DCB1 box drastically shorter first, maybe there is an issue there.
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Old 15th March 2012, 11:55 PM   #1717
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Quote:
Originally Posted by Salas View Post
This circuit has been designed to have optimum bandwidth with up to 20K ish pots. 50K is not recommended both technically and subjectively. In case you insist, substitute the parallel input resistors from 220K to 560K.
Can I run a 10k pot successfully? I will be experimenting with a transformer input that wants a 10kOhm load.
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Old 16th March 2012, 12:08 AM   #1718
Salas is online now Salas  Greece
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10K pot OK. You have a transformer coupled output source that needs see 10K load, yes?
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Old 16th March 2012, 12:15 AM   #1719
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Salas, I am going to try transformers connected to the DCB1 inputs, and those transformers want to see a 10kOhm load on their output, which is the pot. Yes I think we understand each other. Thank you.
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Old 16th March 2012, 03:21 AM   #1720
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Is there an optimized way to route the signal wires? I can either have short wires from the RCA jacks in the rear or to the pot but not both. I guess I can have an extension shaft to go from the front to the rear. Is that necessary or am I being overly anal about this?
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