B1 Buffer Preamp

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Blues

Blues

Member
Joined 2003
parodielin said:
Do I need to check cap value as well? I don't have a tool to check. I went to Sears and found these:

http://www.sears.com/shc/s/search_10153_12605?keyword=digital+multimeter&x=0&y=0&vName=

Which one would work or none? :confused:
Click to expand...

Just check what's on label for now. I usually do a quick check out of circuit before I mount it using an ohm meter set on the highest range or auto range...short cap leads to discharge then +/-probes to cap +/- and you'll see the resistance reading go from low to high as the cap charges. On medium to big electrolytics always use protective gear when discharging.
 
wushuliu

wushuliu

Member
Joined 2008
parodielin said:
I am reporting back on the left channel louder issue with my B1. I got the Gigawork Stereo Pot, changed it, and there might be a short moment that I feel it's balanced. Now the left is again louder but not as loud as the Alps Stereo pot. So the image is shifted to the left on the Gigawork but not as left as the Alps.

I switched back to my HK 635 as the preamp and the image is again centered.

1. Using one stereo pot.
What should I do? If there is something wrong with the preamp, how can I locate that? Could that be a bad resistor or cap? The volume pot doesn't seem to be an issue here. I am trying to work on a solution without involving two pots.

2. Using two pots - Could I use Gigawork pot and Alps pot for each channel? They are different designs so it might not be ideal but for a test, it might work. Gigawork pot has 21 steps. If I use two of them, would I be able to adjust them precisely using steps? Or is it better to get two PEC Log pots?

My final question is: if I can achieve a center image with HK 635 using a single pot, why not Pass B1 using a single pot?

Thanks a lot - it sounds really good so I want to make it work.
Click to expand...

Something isn't right. Don't know if you've already done this, but check/reflow your solder work. A decent DMM starts at ~$50 unfortunately, but it's mandatory for diy troubleshooting and they're worth every single penny...
 
P

parodielin

Member
Joined 2010
wushuliu said:
Something isn't right. Don't know if you've already done this, but check/reflow your solder work. A decent DMM starts at ~$50 unfortunately, but it's mandatory for diy troubleshooting and they're worth every single penny...
Click to expand...

I know. Now I have to evaluate whether I should buy a Maverick Dac/Preamp or try to troubleshoot this one.

Anyone has a link to a usable DMM for this case?
 
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parodielin

Member
Joined 2010
AndrewT said:
none of those 4 Sear's DMM are any good for our use.
You need 600Vdc to 200.0mVdc and 300Vac to 200.0mVac as maximum scale on a 2000count meter.
A wide range of resistance 20M00 down to 200r0 is usually good enough.

Any extra ranges are simply nice to have but not essential.
Expect to pay <$10 or <£7 for a basic DMM that reads to those scales and guarantees <0.5% +-1LSB on it's most accurate DCV scale.
Click to expand...

Andrew,

I will try to locate one but if it's not too much trouble, do you have any recommendation online that I can reference?

Found this one on Parts Express:

DMM with Tilt Display http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-545


Ken
 
Last edited:
wushuliu

wushuliu

Member
Joined 2008
A

AndrewT

R.I.P.
Joined 2004
parodielin said:
Andrew,

I will try to locate one but if it's not too much trouble, do you have any recommendation online that I can reference?

Found this one on Parts Express:

DMM with Tilt Display DMM with Tilt Display | voltage SPL lcd display LCD dmm display DC ac abs Over15PerOffTestandMeasurement | Parts-Express.com


Ken
Click to expand...
this one does not do 200.0mVac.
Post 2448,
the upper one is missing the three lower sensitivity Vac scales.
The lower one is missing both Vac and Vac lower sensitivity scales.

keep searching.
 
Last edited:
W

wim

Member
Joined 2003
Result for so far. Almost ready as you can see.
 

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parodielin

Member
Joined 2010
AndrewT said:
this one does not do 200.0mVac.
Post 2448,
the upper one is missing the three lower sensitivity Vac scales.
The lower one is missing both Vac and Vac lower sensitivity scales.

keep searching.
Click to expand...

Andrew,

Want to make sure I understand your point. For the lower one on Post 2448, the manual says:

VDC range: 200mV, 2V, 20V, 200V, 1000V (missing 600V?)
VAC range: 200mV, 2V, 20V, 200V, 700V (missing 300V?)

When you said "missing both Vac and Vac lower sensitivity scales" (Did you mean Vac and Vdc?), which ones are missing (600V VDC and 300V VAC)?

Thanks!
 
wushuliu

wushuliu

Member
Joined 2008
parodielin said:
Andrew,

Want to make sure I understand your point. For the lower one on Post 2448, the manual says:

VDC range: 200mV, 2V, 20V, 200V, 1000V (missing 600V?)
VAC range: 200mV, 2V, 20V, 200V, 700V (missing 300V?)

When you said "missing both Vac and Vac lower sensitivity scales" (Did you mean Vac and Vdc?), which ones are missing (600V VDC and 300V VAC)?

Thanks!
Click to expand...


Amazon.com: Mastech 30-Range Digital Multimeter with Capacitance…

better

http://www.amazon.com/Mastech-MS826...ref=sr_1_2?ie=UTF8&s=hi&qid=1275850668&sr=8-2

This one does inductance as well, which if you continue on w/ speakerbuilding and other diy down the road - you will
want this function. It's a chunk of change but a good multimeter is a necessary investment.
 
Last edited:
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parodielin

Member
Joined 2010
Thanks! I think the first one lacks Vac 200m. I found this one:

Amazon.com: Mastech Digital Multimeter & LCR Meter, MS8222H: Home…

This one has inductance and is similar to the second one. Just that it's for free shipping.

I adjusted a little bit on the speaker position - I moved the right speaker a bit closer. The image is better this way. I might be able to get away with this for a short while before I have time to troubleshoot the unit. The sound is very good that I don't want to switch back to HK 635 as the preamp.

wushuliu said:
Amazon.com: Mastech 30-Range Digital Multimeter with Capacitance…

better

Amazon.com: Mastech MS8269 31-Range Digital Multimeter & LCR Meter: Home Improvement

This one does inductance as well, which if you continue on w/ speakerbuilding and other diy down the road - you will
want this function. It's a chunk of change but a good multimeter is a necessary investment.
Click to expand...
 
A

albertob

Member
Joined 2009
Hello,
I finished my B1. I mounted two buffers B1 with a stepped resistor attenuator with digital control:

http://www.diyaudio.com/forums/digi...ally-controlled-relay-volume-regulator-2.html

Some considerations:

- My system has two main speakers and two subwoofers digital filter. My preamp has two buffers B1 to control separately the main speakers and subwoofer. There is a delay of the signal to integrate well the sub (phase).
- Bypass the signal to integrate into a home cinema.
- Delay relay for on and off to protect the speakers.
- Mute
- Control via remote control

I am very happy with the device. It sounds really good, very transparent and silent. Thanks to Mr. Nelson Pass for his design of buffer.

I have only one little problem I want fixed. A small crack or "click" when turning off the device. Mr. Pass said:

"If you hear a" snap "when turning off equipment, it Likely
Means That You Do Not Have Some capacitance across the
Or the AC line switch to suppress the transient When You
Which Is Flowing current interrupt. My method is to prefer
AC LINE RATED Have filter caps across the line and Before
After the switch - values like 0.1 uF to 01 uF. "
Click to expand...

But I do not know how to connect the capacitor ... in series with the switch?, My current line is 220V.

I want to upgrade the power supply of my b1. Currently I have the following scheme built into the device:

An externally hosted image should be here but it was not working when we last tested it.



Can you advise me a better supply?

THANK YOU!

Some pictures of my "baby"

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


Excuse my bad English

BR

AL
 
regiregi22

regiregi22

Member
Joined 2009
haciendodelpunkunaamenaza.blogspot.com
albertob said:
Hello,
I finished my B1. I mounted two buffers B1 with a stepped resistor attenuator with digital control:

http://www.diyaudio.com/forums/digi...ally-controlled-relay-volume-regulator-2.html

Some considerations:

- My system has two main speakers and two subwoofers digital filter. My preamp has two buffers B1 to control separately the main speakers and subwoofer. There is a delay of the signal to integrate well the sub (phase).
- Bypass the signal to integrate into a home cinema.
- Delay relay for on and off to protect the speakers.
- Mute
- Control via remote control

I am very happy with the device. It sounds really good, very transparent and silent. Thanks to Mr. Nelson Pass for his design of buffer.

I have only one little problem I want fixed. A small crack or "click" when turning off the device. Mr. Pass said:



But I do not know how to connect the capacitor ... in series with the switch?, My current line is 220V.

I want to upgrade the power supply of my b1. Currently I have the following scheme built into the device:

An externally hosted image should be here but it was not working when we last tested it.



Can you advise me a better supply?

THANK YOU!

Some pictures of my "baby"

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


Excuse my bad English

BR

AL
Click to expand...
All I can say is WOW!!! Impressive design, how did you get the enclosure? Is from Group buy or did you do it yourself? Really pro looking...

For a better PSU, there is an improved version (well, let's say....different) of this B1 buffer which is DC coupled (no need to capacitors in the signal path) and has a far better PSU based on a shunt regulator. You could use the shunt regulators to power your already built B1. Is what Andrew says "Salas shunt regulator". By default, it gives you +/-10v, but can be easily tuned. There is actually going on another Group buy for boards, here more info:
http://www.diyaudio.com/forums/blogs/tea-bag/173-second-round-dcb1-group-buy-has-begun-1-1-2010.html
 
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