About to buy MA-1 monos- how long do the tubes last and how easy are replacements to source?
- Thread starter Nuforce
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It doesn’t matter—just remove the same number from each side of each amp and make sure the offset zeroes.
What caused the (presumably sloblow) fuses to blow in the first place? Did you have tubes arc over?
Only one b+ fuses went, and today on the same amp the corner voltage regulator tube died, so I think that was the issue, bad 6sn7
Just a FWIW: we've seen a lot of cheap fuses marked as slow blow that simply are not. So these days a good quality fuse (Littlefuse, Bussman or the like) is recommended to avoid a lot of hair pulling!
The CCS we use is a 2-stage device; most of the CCS circuits we've seen leave performance on the table on account of being a single stage.
Amps in their final place. So pleased with them, look and sound stunning.
I have x3 pairs of shuguang black treasure cv181-z coming tomorrow.
So awesome! We live in a small loft so my desire for Atmosphere amps is tempered right now. Definitely on my list when we move in a couple years..
I like the design atmasphere .
Looks like a old school solid indestructable piece of gear
I've corrected the tube position, black tube on right hand unit should be on the left, it's a GTB tube
When using NOS tubes usually we recommend a GTB in the position in the corner, facing the power tubes, as seen in the right hand amp in the photo above. The Chinese 6SN7 (the ones with the maroon base) are marked as GTs but are actually GTBs. But I suspect the tube with the black base to be a better sounding tube; if it were me I'd put it in the middle location of each amp.
When you changed out the tube in the corner facing the power tubes, don't forget to check the DC Offset, since that tube controls the bias and DC Offset for the output tubes.
Congrats! Welcome to the MA-1 club! I’ve had my Silver Editions for over a decade and still enjoy them immensely. I will be curious to here your 6SN7 impressions as time goes forward.
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Sorry to hear that. So, they are going back to Ralph and company? Atma-Sphere products are pretty bulletproof you will find, so once they are right, they stay right. Most often, a tube is the only problem, if at all.
Atmasphere circuits are extremely logical and straightforward - in the rare case of problems, a joy to diagnose and repair, particularly as they are point-to-point wired and very accessible.
Since these were just shipped, more than likely you simply had a power tube fail rather than the amp itself. During the first week or two after installation is when we encounter the most problems with power tubes.
It the amp simply stopped playing, its likely the fuse by the power cord blew; this fuse can blow if a power tube arcs. Usually its a simple matter to replace the fuse and locate the arcing tube by simply knocking on the tops of the tubes.
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