[jamont]

I've got a working MINT board now. It was easier than I had originally thought to build. Soldering the SMD chips was not too bad (and I didn't smoke any). What helped me most was 1) using a small tip soldering iron and 2) fine gauge solder (.020 I think). I never came close to making a solder bridge. The layout is very nice.

The sound is excellent with Senn HD580, no obvious difference from my META42's. I'm using a OPA2134, inner loop gain of 80, overall gain about 10, BW pins open for now. Power was a 24V wall-wart.

The wall-wart is unregulated. I can hear the ripple (hum) with the META42 and see it on the scope, but I don't hear it with the MINT. I'm puzzled about this, maybe the OPA2134 has better PSRR than the AD8620 in the META? I'll have to do some more experiments.

The hard part remains - possibly cutting the board in half and putting it in a case. I did find that the clearance required for a board mounted Pana pot is about the same (20mm) whether you cut the board or not, so I may not risk it...

 

[Noesis]

I should look into using wall-warts made for electric guitar effects and such. I use Boss wall-warts for my guitar effects pedels and get no ripple out of them. If I use a typicall wall-wart, it's hummin' as long as its on.

Go to the nearest Guitar Center and pick one up. I bet that will help.

-Chad

 

[mekanoplastik]

hi Jamont...

congrats for your amp...you got me interested

...you say the sound is hardly noticeable from a meta, what configuration do you have in the meta? also. can you add jumper pins in the buffers to test the difference?

m.

 

[jamont]

Quote:

Originally posted by mekanoplastik hi Jamont... congrats for your amp...you got me interested ...you say the sound is hardly noticeable from a meta, what configuration do you have in the meta? also. can you add jumper pins in the buffers to test the difference? m.

The META has AD8620, EL2002 buffers, inner loop gain 200, overall gain 7 or so, 4x1000uF Pana FC, external regulated 24V power supply. On parts quality, this is better than the MINT (and indeed sounds excellent), but the MINT is very close. It sounded very good on demanding material (Shostakovich Symphony No. 15).

The MINT has provision for jumpers (or resistors) to enable the wide bandwidth mode of the BUF634. They are sized for a resistor so you can't use a standard 0.1" jumper however. I plan to rig something to try it, but I haven't done so yet.