| Pdspecl |
Good morning,
My brother sold me his SA-100 hybrid amp for $250.00. Has low
hours and works fine. I've found someone who will upgrade all coupling caps & elect caps to Dynamicap, Solen....Black Gate, and hexfred diodes for around 400.00 parts and labor. I've been doing some research on DIYaudio and evidently there are some design issues with this amp. So, is it a wise investment (bang for the dollar) to upgrade this amp.
I'm currently using a Michael Elliot modified Counterpoint SA-1000 preamp and power hungry Mirage m7si bi-polar speakers.
Please offers suggestions or alternatives. Note, I prefer hydrib tube amps. I did try using a CAYIN A88-T as a straight amp with the Mirage speakers. It sounded nice but the bass was anemic. :whazzat: |
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| KBK |
I'll take it. You don't need it. :p
It's a gamble. The fets tend to degrade. Look for a 'magic smoke' thread, by me, to see what one looks like when they pop.
If you can find it, the Precision fidelity M-8 unit is far more reliable, and an easy upgrade. And NO, I'm not parting with mine.
I'm in the process of rebuilding mine, and the whole parts upgrade and full transformer swap is costing me..oh...$300 in parts. True, the work is all mine. As for the amp.. damn, it's a fabulous sounding piece, and I've heard just about everything (design wise) out there.
I have two SA-220's..and now, today, I'm a gonna get brave..and start messing with the faulty one.
What it MIGHT be wise to do, is to invest in a 'channel' for a SA-220, (used fets) from Mike elliot. (alta vista audio)..this would give you replacement fets for two channels of your SA-100, which should keep you going for years, if ever a channel fails. You get two channels, as a SA-100 uses exactly half the nuber of fets that a SA-220 does. Only one channel fails at a time.
See the scary photos in my 'magic smoke' thread. |
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| Pdspecl |
Do you think the $400 spent on upgrades for caps and diodes with yield an decent improvement in sound eventhough I'm keeping the original circuit design?
What recommendations would you make for any circuit design changes that would still keep me under 500.00 total cost.
I'd like to get a Plitron transformer by these go for 400.00 as per Michael. Is there another brand model transformer I could use that would be better than the original unit? |
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| KBK |
You would really need to know what you are doing to go down the road on this one, on your own. Counterpoints are fine on their own, but if you start messing with them, they can go poof.
Simple parts swaps will work wonders for any amp, and the counterpoint is no exception.
In my humbe onion, the tranny is a expensive upgrade for the sonic return. Best to let this guy do all the other work, if he knows what he is doing.
The transformer can be done in pieces, at a far cheaper price. What I mean, is two separate transformers for the unit. One for the tube stage, and one for the power stage. It would likely come in at half the price of the plitron and you'd be far better off for it.
That's the way the M-8 Precision Fidelity is made. Two separate transformers. I'm keeping the tube section transformer, as is, and replacing the power section transformer, to dual mono, a pair of 400 VA units, torodial units off ebay, from 'antek', $ 40 each. You'd need three,and the space for them. And you'd have to know the voltage values. Mikey was kind enough to write it, right on the trannies.
Changing the circuit of the conterpoint is, straight from a guy (not me) who used to be an authorized service center for them , is: 'not a good idea.' |
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| Pdspecl |
Moderator,
I'd like to emil the person that provided me feedback so I can get additional information regarding upgrades for my amplifier. Is this possible?
Regards |
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| Netlist |
It is now.
/Hugo :) |
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| anatech |
Hi Pdspecl,
I used to be authorized warranty for Counterpoint.
Either leave it alone, or there are heavy changes that should be done. The transformer is a complete waste of money as are the other mods for now. The changes needed are so fundimental that you should leave it alone until it fails.
The very best thing you can do is this, install a set of 6922EH. Do not install any other tube type in it. Heater current is a big concern here. You may have to play with tubes to equalise the gain. There are two controls that should be shorted out. VR3.
Make sure your bias is low enough. It takes this amp at least 1/2 hour to settle down with the cover on!!!.
Make sure it runs in a cool spot, DO NOT LEAVE IT ON!!
-Chris |
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