Sumo Andromeda predriver advice

[vita]

Originally Posted by Kindhornman

Stephano,
When I was showing my speakers at the CES show in Las Vegas one year Sumo loaned me amplifiers to use during the show. I liked the sound very much and thought that later I would purchase one of their amps. But alas what happened was that Sumo shut down production. I remember reading something in their history about this but don't remember exactly why it happened. I think the designer passed away at some point if I am correct. So though these were nice sounding amps they haven't been available for a long time. I have some Parasound amplifiers that just never had the full bodied sound of the Sumo. Actually I have an older Harmon Kardon amplifier that sounds better than the Parasounds. Now to find out if anyone has ever cloned one of these amplifiers? I'll have to put up a post and ask that question.

Steven

Hello Mr.Steven,
Well, me too if I am not mistaken, Mr. James Buongiorno is indeed still alive.
Look at this link:James Bongiorno Designs

Best Regards
Stefano

[qusp]

Steven: Jason Stoddard from sumo is now running a primarily headphone audio company (Schitt Audio, yes you read that right....) making home amps and dacs. i'm not aware of who was the amp designer at Sumo, but Jason was certainly A designer at sumo and designs the amps at Schitt, likes circlotrons and uses a Sumo Andromeda III to drive some large planar panels at home. it might be worth shooting him an email through his website.

[qusp]

wit looks only a mother could love, that blue and gold chassis at James Buongiorno is UGLY

so in short, Steven, if you can remember exactly what amp it was, good chance you'll be able to find the schematic and maybe even PCBs here. there have been recent Ampzilla group buys, ive seen numbers of sumo 9 builds over the years

[llwhtt]

In regards to contacting Jason about SUMO, I contacted him last year and he has NO interest in dredging up the past. He answered some Andromeda II questions for me but wasn't interested in doing anymore.

Mike Moffet from the original Theta is there also but has no interest in the past either.

Craig

[vita]

Happy New Year to all,

I would like to complete this thread, but I have some problems to find certain components.
I would like to know if anyone knows the difference (if there is difference) between MPQ6001 and, SPQ1561 I found the datasheet of the IC MPQ6001, but not the SPQ1561.
My amp is installed SPQ1561,One is partially dead,for me, they are hard to find,
is that they are interchangeable?,
because surplussales Nebraska, has in stock MPQ6001, and in this case, I can change the four IC.

Thank you,
Best Regards

Stefano

[llwhtt]

Both should work equally well as both are listed on the schematic and in the service manual. Another alternative is to replace the IC with discrete transistors. If you can find MPSA13 & 63 darlingtons you will only need two transistors per channel. Did you try searching for MPQ6001 on this forum, there are several prior postings concerning this IC and alternatives. Whatever you end up doing make sure the IC/transistors are in contact with the heatsink, use thermal compound too.

Craig

[vita]

Hello llwhtt,

thank you for your prompt response, if I can get DIP14 version is simpler than the TO-92, because there is a height problem,
even if the modification of the support, which also supports the transistors Q15-16-17-18,is not too complicated.

Stefano

[vita]

Hello,
after a few months, I take this discussion, I had to wait a long time, the time to find all the components at the last moment, a channel came and went, it was the diodes and 2sa968 who had died, even if measured well (the amp was mounted with 968-2238-y and y, instead of 968B-y-y and 2238b).
I also found the sa818, sc1628, with great difficulty, but after listening, I preferred the sa1145 and sc2705, they go very well with a 60mA bias and are much more transparent, the 818 and 1628 asked a bias very high, if the distortion was audible.
It remains for me that changing the power transformer is very noisy.
Apart from a few original resistors else is new (this amp is not a deal but it is very good).
I had a question about the secondary voltages, as for 42volt, I measured 47volt and 48volt for I measured 55volt.
Does it may be appropriate, or it is better to have tensions closest as that recorded in the diagram.
stefano

[vita]

Hello,
after a few months, I take this discussion, I had to wait a long time, the time to find all the components at the last moment, a channel came and went, it was the diodes and 2sa968 who had died, even if measured well (the amp was mounted with 968-2238-y and y, instead of 968B-y-y and 2238b).
I also found the sa818, sc1628, with great difficulty, but after listening, I preferred the sa1145 and sc2705, they go very well with a 60mA bias and are much more transparent, the 818 and 1628 asked a bias very high, if the distortion was audible.
It remains for me that changing the power transformer is very noisy.
Apart from a few original resistors else is new (this amp is not a deal but it is very good).
I had a question about the secondary voltages, as for 42volt, I measured 47volt and 48volt for I measured 55volt.
Does it may be appropriate, or it is better to have tensions closest as that recorded in the diagram.
stefano