Salas hotrodded blue DCB1 build

[Salas]

As long as you got no buzz from a transformer field over the signal wires, do as you please.

 

[pinnocchio]

I've a component selection very similar to yours, try those caps...



Sadly no, too much reverbs.

Maybe Silmic first version (ROS)

Why not use the Mundorf M-Lytic Bi-polar? Those are really good and have low ESR

Do

 

[Siberia]

Wired my Tx directly to dcb1. No luck getting better results.

 

[Salas]

Is there anything wrong periodically with your mains quality maybe? So your system comes and goes over a few weeks?

 

[Tea-Bag]

Siberia - maybe a few very good result ion Jpegs would help look for any nasties.
Is there a cap across the AC, like .0033 to 0.1uf X or Y rated?

 

[Salas]

Should check the mains don't go south and the Vin - Vout margin drops too much is one thing.

 

[Siberia]

Those comes and goes always had a reason that I or we have discovered eventually. Bad grounding, badly soldered wire, etc... Mains quality never played a role on it.

How do I check the "going south" thing?

These are most recent measurements:

VDC -10.30; + 10.24
VACin -16.60; +16.72
DCout -1.6; +0.9

Here are some pictures.

http://wtrns.fr/BroYUZKEF8JCGU

I could additionaly make every angle you ask.

 

[ClaveFremen]

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.

Do you have different shunt resistors to try?

While those naked Vishays are the best for direct signal path I don't think they're as good for shunt... you need something that sounds bolder like PRPs or carbon films IMHO.

 

[Siberia]

ClaveFremen, do you mean current setting resistors?

 

[Salas]

Those comes and goes always had a reason that I or we have discovered eventually. Bad grounding, badly soldered wire, etc... Mains quality never played a role on it.

How do I check the "going south" thing?

These are most recent measurements:

VDC -10.30; + 10.24
VACin -16.60; +16.72
DCout -1.6; +0.9

Here are some pictures.

http://wtrns.fr/BroYUZKEF8JCGU

I could additionaly make every angle you ask.

The way you checked is OK. Shows your mains are high enough to give margin. Regarding the pictures, maybe its better you solder the in/out wiring directly under the PCB on the connectors pads? Since you say it was always a contacts or good grounding thing, maybe worth a try.

 

[ClaveFremen]

ClaveFremen, do you mean current setting resistors?

No, the two 220K and 1M, see attachment.

 

[Siberia]

Dario, I've tried carbon films and other resistors in those and all critical positions previously. You are right, carbon films sounded bolder. But I prefer "nakeds" for their uber transparency. My problem is on bigger scale than mere tonality...

I wonder could it be heard on the file I have attached?

Salas, I've just followed your advice. Signal wires straight to pcb under it. Same sound.

I wonder also if could it be an amp related problem. For example bad amp rca connection?

 

[Siberia]

If I had to describe what sound I'm getting, I would say it's all perfect except that somebody turned down low region knob on invisible eq.

 

[Salas]

I wonder also if could it be an amp related problem. For example bad amp rca connection?

Weird stuff. Since its about anemic low region you are right to suspect possible power stage related issues also. A DC line stage why to periodically cut on bass if all healthy its beyond me. You need some tech tests and related equipment data so we can really say for that system as a whole. Or some luck with trial and error on connections and parts.

 

[AndrewT]

VACin -16.60; +16.72
DCout -1.6; +0.9

I don't understand these measurements.

 

[qusp]

I presume thats supply voltage for the rails and DC offset (signal) at the output, not exactly the most intuitive way to write it

 

[Siberia]

I don't understand these measurements.

Tx secondaries: 16.60V; +16.72
-1.6; +0.9 is Dc offset on output.

Sorry, if it's counterintuive.

 

[Siberia]

On my suspicion list one power amp rca which feels to have a looser connection then the other. I can tighten the plugs to grip well, but I wonder could it create the problem where "the nose" of connector it's not touching properly the conductor inside the socket?

 

[Rikkert1978]

I finaly managed to complete my Tea-bag Kit Dcb1 build.
The kit was very easy to use, and everything seems to work also!

I do have one measurement that is kinda well... Weird.

My Vout+ and Vout - are almost the same. 9.95V and 9.94V. What I read in the manual the Vout + should be higher then Vout- ? Is this bad?

The rest of the measurements:

Voltage drop on the power resistors: 1.764V and 1.861V

The output: Right 1.6mV dc
The output: Left 1.8mV dc

Led string -9.31V and +9.32V

I am using btw a 12v transformer, (for testing) would a 15 volt one be preferred?

 

[Salas]

In Hypnotize both rails tracking close is the right thing. In Mezmerize a bit apart is the right thing. So yours is OK. To tell if your OK with your Tx on your mains, give us the DC in value. You can measure it under one of the big filter capacitors.