Salas HOT ROD DCB1
Posted 15th June 2010 at 03:56 PM by Tea-Bag
Updated 2nd March 2013 at 11:08 PM by Tea-Bag (added BOM)
Updated 2nd March 2013 at 11:08 PM by Tea-Bag (added BOM)
So I am going to write some details down about the DCB1 Blue Edition Buffer. This is the best I can tell, the third or fourth iteration of this buffer/Power supply. The GB will certainly represent the third run of the buffer.
Salas added some tweaks to the design which CRT implemented. I will be offering these boards for sale.

Here are some things that make it different,
It's a larger board.
More room for filter caps.
They can handle 10mm pitch snap-in capacitors 25mm width capacitors.

There are positions for smaller MUR120 type diodes or MUR820 style TO-220 style diodes.
The vRef LEDS can now be bypassed with a 25mm Film cap or a 100uf electrolytic.

The CCS resistor is now about a 28mm pitch, and can easily handle most 5 watt wirewound type of resistors.
2oz copper is used in board, the holes are through hole plated.
There is a 3 pin connector at end of power supply section for easy hookup if the device is used as a stand alone shunt supply.
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Here are some specifics on the board in the pictures. It is a prototype without a top soldermask. The production units will have a more traditional looking blue soldermask with white legend.My board is complemented with the following notable parts. I went a bit over the top. Wishing I had sprung for the super-through Nichicon's.
B1 signal resistors
Users sound implementations will vary.
Compared to my standard DCB1,
The sounstage is is very tight. The clarity is up a notch as well. When I get spooked by the soundstage, I consider that a good thing.
I hooked these up to DX4 lowthers and there is no noise from the setup.
The price of the board is 15.00 each. Shipping is 6.00 each for up to 4 units. 5-8 units 8.00 and above 8 units, please send me a private message.
Here is a build guide another member did.
It is excellent, and on audiocircle. Thanks Wushiliu
DC-Coupled B1 Buffer Build
Here is a example of a balanced setup that works. Special thanks to johnwmclean and nycavsr2000 for this work.

Regarding grounding of the balanced project.
FYI the signal return on both boards are connected to ground chassis via a ground loop breaker as follows;
The ground loop breaker is a 10Ω 5W resistor in parallel with a 0.1µF capacitor rated at least 250VAC. For safety this capacitor should be rated for class X or Y (good for across-the-line use) with flame retardant casing.
Just so you truly believe, here is the real deal.

Nice casework, huh?
Salas added some tweaks to the design which CRT implemented. I will be offering these boards for sale.

Here are some things that make it different,
It's a larger board.
More room for filter caps.
They can handle 10mm pitch snap-in capacitors 25mm width capacitors.

There are positions for smaller MUR120 type diodes or MUR820 style TO-220 style diodes.
The vRef LEDS can now be bypassed with a 25mm Film cap or a 100uf electrolytic.

The CCS resistor is now about a 28mm pitch, and can easily handle most 5 watt wirewound type of resistors.
2oz copper is used in board, the holes are through hole plated.
There is a 3 pin connector at end of power supply section for easy hookup if the device is used as a stand alone shunt supply.
___
Here are some specifics on the board in the pictures. It is a prototype without a top soldermask. The production units will have a more traditional looking blue soldermask with white legend.My board is complemented with the following notable parts. I went a bit over the top. Wishing I had sprung for the super-through Nichicon's.
- Nichicon Gold Tune 4700uf capacitors
- IXYS DSEI8-06A diodes
- 470R takman carbon film gate resistors for IRF's.
- Mills 10R MRA-5 resistors for CCS.
- Wima MKP-10 .22uf vRef bypass
B1 signal resistors
- 220R Texas Instruments TX2575 foil resistors
- 220K Caddock TF-020 Film resisor
- 1M Caddock MK-132

Users sound implementations will vary.
Compared to my standard DCB1,
The sounstage is is very tight. The clarity is up a notch as well. When I get spooked by the soundstage, I consider that a good thing.
I hooked these up to DX4 lowthers and there is no noise from the setup.
The price of the board is 15.00 each. Shipping is 6.00 each for up to 4 units. 5-8 units 8.00 and above 8 units, please send me a private message.
Here is a build guide another member did.
It is excellent, and on audiocircle. Thanks Wushiliu
DC-Coupled B1 Buffer Build
Here is a example of a balanced setup that works. Special thanks to johnwmclean and nycavsr2000 for this work.

Regarding grounding of the balanced project.
FYI the signal return on both boards are connected to ground chassis via a ground loop breaker as follows;
The ground loop breaker is a 10Ω 5W resistor in parallel with a 0.1µF capacitor rated at least 250VAC. For safety this capacitor should be rated for class X or Y (good for across-the-line use) with flame retardant casing.
Just so you truly believe, here is the real deal.

Nice casework, huh?
Total Comments 5
Comments
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Okay, so I have updated my DCB1 a little bit lately.
Here is the parts list
VALAB 23 Step Attenuator Potentiometer 20K Stereo Log (ebay) I think it is just a series resisistor setup, but it performs nicely, small 2db steps. Before I was using a 20 or 25K precision instruments, or whatever Nelson used on origial B1.
Diodes were swapped for
Cree C4D02120A Silicon Carbide units 1200v 2A.
The Mills MRA-5 were swapped for
CW0053R300JB12 3.3R Vishay 5W resistor 30PPM
These are big bad boys, rated to 6.5W I think. Not easy to fit in. This runs it ~600mA, and the ambient temp is now 42C in the box. Probably need to drill some more holes in the chassis.
And lastly a Greyhill 2 pole 5 position switch. Nice noiseless unit. 71BD36-01-2-AJN
The tone here does not change too much, maybe a touch more body. What I do get is a better localization and depth of image or more well defined sweet spot.
Changing the pot and switch were done later, and did not change the sound much IMO, things are still breaking in and getting better. At first after the changes, it took on a darker tone, appearing to obscure the highs, but this went away after a few hours of burning in, and is gone now after a few days.
Next up to bat, is replacing the signal wire with all OCC type solid core 6N copper wire.Posted 30th November 2011 at 11:30 PM by Tea-Bag
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Posted 15th December 2011 at 10:33 PM by pinnocchio
Updated 25th July 2012 at 07:38 PM by pinnocchio -
DCB1 Parts Kit Current
Part Manufacter part qty
Relay diode 512-1N4001 1
10R Dale 5W 71-CW0055R000JE12 2
TO-220 Heat Sink 532-6043PB 1
Nichicon Muse 100uf 3
BC517 863-BC517G 1
BC550C Fairchild 2
BC560C Fairchild
Diode 600v 8A 512-FFPF08S60STTU 4
7812 511-L7812ACV 1
relay bypass cap 505-MKS02.1/63/10 1
Relay TQ2-12V-3
header male 538-22-23-2031 2 2
header female 538-10-11-2033 2 2
header pins 538-08-50-0114 10
IRFP 240 844-IRFP240PBF 2
IRFP 9240 844-IRFP9240PBF 2
connector block 571-1776119-3 2
TSHA 4700uf 667-ECO-S1EA472BA 4
Wima MKP10 .22 400v 5% 2
10R PRP Resistor Kit 2
100R PRP Resistor Kit 2
470R PRP Resistor Kit 4
2.2K PRP Resistor Kit 1
10K PRP Resistor Kit 1
47k PRP Resistor Kit 1
220R PRP Resistor Kit 4
220K PRP Resistor Kit 2
1M PRP Resistor Kit 2
Matched quad 2SK170 and 6 random Toshiba NOS 2SK170 10
DCB1 Black 1
LED RED 20ma 30Posted 17th December 2011 at 01:05 PM by Tea-Bag
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Hi Teabag,
Would it be possible to acquire a board from you?Posted 28th February 2012 at 09:17 PM by jtrompetter
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Posted 16th March 2012 at 10:54 PM by Tea-Bag



