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GB for DC coupled B1 buffer with shunt PSUs

That is the very first batch with the low voltage relays GB and everything most surely.
5V relays can be a much heavier load especially in a Mez where 2 are driven in parallel at any time. Strap a small size 0.1u cap -ceramic, MKT, whatever- between B,C pins of 517 underneath PCB and see if it stops the mechanical chatter.
 
P.S. What kind of voltage is driving the relays? Because I also see you utilized the jumper. If there is a 7812 there and a jumper, you push them. There must be voltage drop on that resistor parallel to the jumper for 5V relays from 12V reg chip or you mixed things. If that is the case replace the jumper with another same resistor.
 
No - there's no jumper - that was a pic I took from earlier in the thread.... just the same model board as mine.


I have a 7812 there, I get 5.7V drop across the dropping resistors which should give me just over 6V to the relay.

I'll pop in the cap tomorrow night and retest.


Fran

ps. thanks for the help!
 
Ah, I couldn't leave it til tomorrow night. Turns out it was actually a BC550 where it should have been a 517 - and now that I've thought about it I think the 517 was the recommended part, but I couldn't get it or something.

Anyway, I put in a 0.22uF mkt and the chattering is gone. I fixed up one or 2 loose RCA jacks etc as well when I was in there.

Thing I can't understand is how did I not notice this at the build stage. I did a lot of experiments with pots, and current in the shunt, so I ran it for a long time with no cover and I would have heard the noise if it was there. Could it be that it only started after some time?#


Alls well that ends well. Thanks again to teabag and Salas for your help.


Fran
 
Can some one xplain how excatly would be possible to sign up and get boards/kits/components? I seen the Tea-Bag's Sign up Sheet Round #2 2012, but not sure if this the one and valid? What is the definition for MiniKits in different columns?

Hi,
The First couple columns in that spreadsheet relate to the DCB1, one for the board, and one for a kit of parts (full) to go with it.

The kit info is here.

http://www.diyaudio.com/forums/swap-meet/197590-dcb1-black-white-red-kits.html#post2729473
 
Just to clarify, is this kit for DCB1 is the "DCB1 Mesmorize BLUE PCB" with several inputs switched by relays?
If I need for two channel/stereo system should I order two sets of PCBs and kits? By reading severa threads still did not catch the differences between different DCB1 versions.
 
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Ok, I got the point, both channels on one board, but I would actually need the "DCB1 Mesmorize BLUE PCB" with several inputs switched by relays. Is the relays and the capability to use several different components sizes are the only main differences between Mesmorize and Hypnotize versions?
 
Tea-Bag, thanks for clearing things up.
I will do simple, will stay with your GB for Hypnotize version, keeping my entry on Sign up Sheet Round #2. Hypnotize version will be a perfect option. Multiple inputs selection, volume regulator I will wire in separately, point to point or will make my own, separate PCB for it.
 
HI Tea Bag, is there another group buy upcoming for the boards? I found the link to google.doc spreadsheet for the group buy but was not sure if that was the one that just finished. At any rate, I would like 2 boards if you reorder.

By the way the DCB1 kit that I bought from you this summer was real nice and went together easily. Best, John

John,
I see your name there.
It looks like demand will be good enough to make another run of these.
I think it is a few months out for close of it.