• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

BTSB Buffer - SE/Bal to SE/Bal Buffer GB

Founder of XSA-Labs
Joined 2012
Paid Member
I just ran same test with BTSB Panel Mount that uses OPA1637 balanced line driver.

Same result - works fine and delivers about same 48.8Vpp with 4.9Vpp input.

1676816577793.jpeg

Small glitch on O-scope probably due to function Generator in O-scope being driven too hard. Lowering it to get exactly 40Vpp gives nice trace:
1676816923712.jpeg

1676816518173.jpeg

Fluke TrueRMS DMM shows 17.30Vrms or 48.95Vpp.

So I think we are good to go with either version being able to drive and F4 to 40Vpp.

That tiny OPA1637 is an impressive little chip! 3mm x 3mm 8 pin VSSOP format.
 
Last edited:
Founder of XSA-Labs
Joined 2012
Paid Member
There is not an 18v version of DPAN02 DCDC. You can use external +/-18v but that’s running right at limit of part.

Are you trying to get more than 40Vpp?

I have a HV opamp board that uses the M2X/Yarra format.

150Vpp with 30mA capability. Depending on your rails. The one I have has built in +/-35v PSU DCDC converter. So should have 70Vpp swing (SE).

https://www.diyaudio.com/community/threads/opa454-front-end-for-lufo-amp.373243/#post-7104704

1676819186021.jpeg

1676819200968.jpeg

1676819082281.jpeg

1676819243385.jpeg

You can also use external PSU like above.

I used this on SuSyLu amp which is balanced 100W class A. In balanced mode +/-35v rails gives 70Vpp single ended - so should be able to hit 140Vpp in balanced output. 100w amp needs 80Vpp balanced output.

1676819348510.jpeg
 
Last edited:
Founder of XSA-Labs
Joined 2012
Paid Member
The PCB itself is 132mm wide x 45mm deep as stated in Post #1. The dimensions of the rear panel cutout holes for the output jacks is in this thread Post #1 and also in my shop. I am reposting below. But note that the CTC vertical distance is actually 7.25mm as the RCA jacks that I am using are a little different than the Elecaudio's that were used in the orginal. If you buid your own with Elecaudio jacks then the 8.25mm distance is correct.
1677039083478.png
 
Last edited:
My own concept.

A monoblock with 2 4U x 300 heat sinks each. Wolverine on one heat sink and FH9HVX on the other. BTSB or THAT RXR on back to go from XLR to SE that the amps need. I will use the AllCees PSU in each Monoblock. I will use some modushop parts: MiniD base plate, heatsinks and brackets, Diss 4U backpanels rotated 90 degrees for the rear panel, Diss 5U backpanels for the front panel, 150mm MiniD tops and bottoms. The PSU and transformers will be mounted below the heatsinks. So it would be roughly 230 mm wide x 350 mm tall. The sides of the PSU area will be constructed of wood as well as the decorative front panel. I will be running active 2 way speakers using DIYAudio store active crossover with two BTSBs on the output so to get balanced XLR outputs. My sources are located on the opposite side of the room from the speakers so I decided to use XLR connections for all my amps. I have a little more than 4' between speakers to place amps. So I can get 4 amps in that space without stacking.

Not sure yet if I will hook up both amp boards at the same time or not. I will need to test it out. Plan to use a 400va transformer with 2x40Vac secondaries. 100W or so should be fine.
 
Member
Joined 2008
Paid Member
Only my second time doing SMD work and it’s just as miraculous as the first. I was convinced it wouldn’t work out and magically I ended up with nice shiny joints. I used the hot plate plus hot air rework station method.

Since this is a 1.2 TH board, I’m expecting to cross R42 and R43. Is that correct?
 

Attachments

  • 9B4B7928-1FFE-4ABE-BD51-F28F7F8660E6.jpeg
    9B4B7928-1FFE-4ABE-BD51-F28F7F8660E6.jpeg
    754.8 KB · Views: 91
Founder of XSA-Labs
Joined 2012
Paid Member
No load needed to power up. Are you sure you have polarity correct on the input?

The output is +/-15v and you measure that at the three output pins relative to the middle output pin. The input 12v and GND is isolated by 5200v from the outputs. make sure the DMM lead for -ve is not relative to the PSU GND but to the output GND.

Here is a closeup of the connections and where to check. I may have the +ve and -ve output mixed up but main thing is to measure output voltage relative to the middle pin.

1678671546452.jpeg

ISO means galvanic isolation barrier.
 
Last edited:
  • Thank You
Reactions: 1 user
I am in need of a SE to Balanced buffer for my phono preamp outputs. Can this work for that use case? I have essential tremor in both hands so soldering through hole components is quite difficult, but possible. I suspect that SMD soldering would be out of the question for me. Could I purchase either with the SMD parts already soldered or RTR?
 
Last edited: