@drummerman111. I see that you have posted a similar post in the valves section (there maybe others) - my question is, what are you actually going to do with the answers?
I did read that. It still looks the same to me, that's why the repeat.
But I will bow out.
Jan
As will I, nevertheless, thank you and others for your views. Very interesting and I am aware that this site is far more directed at non commercial products and obviously, DIY. I will follow quietly. A lot of knowledge here.
Agree - its the only one without high current secondary winding leads dangling over the PCB. And yes you can't tell component quality this way, besides its the weakest link that matters, many parts don't need so much "quality", just not to be junk.
Arcam actually does make a "plain" 200W class G power amp with it's dual PS's - real clean layout (below 1).
- Class G switched "Leach" symmetric topology. I think they even use a discrete rail switcher. About .01% @ 20khz - nothing special...
- Niles makes a plain ol' class AB 150W - the SI-275 - https://www.audiosciencereview.com/forum/index.php?threads/niles-si-275-amplifier-review.12055/
Yup . .01% with the same "Leach" front end (below 2/3). Just bought one for $50 broken !!
Easy to reverse engineer , get rid of the ceramic comp. caps , use 33-47pF silver ones. "Leach" can still be VERY stable @ 1+Mhz UG.
Nice to simulate it , works out a little better than spec (the review).
These amps are for commercial HT installations , built way better than typical public junk ! Yup - just bad caps after 30 years.
A couple sketchy solder connections and dirty boards - that's all.
OS
- Class G switched "Leach" symmetric topology. I think they even use a discrete rail switcher. About .01% @ 20khz - nothing special...
- Niles makes a plain ol' class AB 150W - the SI-275 - https://www.audiosciencereview.com/forum/index.php?threads/niles-si-275-amplifier-review.12055/
Yup . .01% with the same "Leach" front end (below 2/3). Just bought one for $50 broken !!
Easy to reverse engineer , get rid of the ceramic comp. caps , use 33-47pF silver ones. "Leach" can still be VERY stable @ 1+Mhz UG.
Nice to simulate it , works out a little better than spec (the review).
These amps are for commercial HT installations , built way better than typical public junk ! Yup - just bad caps after 30 years.
A couple sketchy solder connections and dirty boards - that's all.
OS
Attachments
Here is another good one for the "Mod" - a Acurus A250. Reviewed and tested - https://www.audiosciencereview.com/...s-which-test-well-under-1-000-usd.6250/page-5
EBay - 2-300 broken or 5-600$ working.
LOOK how clean that one is !!! Almost a Wolverine.
It does fall short , being just a overbuilt EF2 (like the badger). But , 5-10 PPM will work.
Any of these amps are quite the jump from any marketed integrated offerings. Just get a E30 topping DAC
and maybe a preamp , good to go. Easier to fix , not "stuck' with anything obsolete.
Best thing , after re-capping and a few tweaks - you won't ever need to buy (more).
If you want to get "nerdy" , put a Wolverine in your case. 1-2 PPM amp to match your 1-2 PPM DAC !
Start building better speakers !!!
Edit - he modded that Acurus bada$$ !! last pix. quite the PS !! "Nerdy"....
OS
EBay - 2-300 broken or 5-600$ working.
LOOK how clean that one is !!! Almost a Wolverine.
It does fall short , being just a overbuilt EF2 (like the badger). But , 5-10 PPM will work.
Any of these amps are quite the jump from any marketed integrated offerings. Just get a E30 topping DAC
and maybe a preamp , good to go. Easier to fix , not "stuck' with anything obsolete.
Best thing , after re-capping and a few tweaks - you won't ever need to buy (more).
If you want to get "nerdy" , put a Wolverine in your case. 1-2 PPM amp to match your 1-2 PPM DAC !
Start building better speakers !!!
Edit - he modded that Acurus bada$$ !! last pix. quite the PS !! "Nerdy"....
OS
Attachments
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This very much has a DIY feeling to it. And looks like an rather easy fix (you could probe in situ...); even the used/working price seems very reasonable, that's probably close to component value. I like it.
Or , add transitional miller (or 2 -pole) feedback compensation to the original to tweak performance.
-Look over the layout details of the amp PCB's for any blaring screwups. Sonance takes feedback from the far end of P or N on their amps.
They were aware of this , made the FB (OP) trace twice as wide. I ran the wire right to the zobel/inductor point.
-Simulate the OEM core amp circuit , you would be surprised that the output matches the manufacturers spec closely.
Consider what the end use of the OEM's market required. A subwoofer amp will have basic design differences than a general
purpose unit.
Many of these amps have "convenience" features like auto turn-on. These can detract from end fidelity.
DON'T disable all safety features . Like some want to get rid of output current limiting/DC , thermal ,fusing.
Access safety versus what perceived "audiophile" gains are desired. Most of the time , I just upgrade in quality.
Use google to access the build quality , a search of images usually gets you the "guts". Schematics are nice , too.
Don't want no proprietary chip amps , unless you just want the case for a full DIY.
OS
I try to get something with local shipping for well under 100. I got the niles for @ 70$. I have the caps , cleaner , and any
other components I may need. Most of these AB amps use Sanken MT-100 pairs.
Edit - those arcams use hard to find "thermaltrak" OP devices. harder to find ?? boo Hoo...
OS
-Look over the layout details of the amp PCB's for any blaring screwups. Sonance takes feedback from the far end of P or N on their amps.
They were aware of this , made the FB (OP) trace twice as wide. I ran the wire right to the zobel/inductor point.
-Simulate the OEM core amp circuit , you would be surprised that the output matches the manufacturers spec closely.
Consider what the end use of the OEM's market required. A subwoofer amp will have basic design differences than a general
purpose unit.
Many of these amps have "convenience" features like auto turn-on. These can detract from end fidelity.
DON'T disable all safety features . Like some want to get rid of output current limiting/DC , thermal ,fusing.
Access safety versus what perceived "audiophile" gains are desired. Most of the time , I just upgrade in quality.
Use google to access the build quality , a search of images usually gets you the "guts". Schematics are nice , too.
Don't want no proprietary chip amps , unless you just want the case for a full DIY.
OS
I try to get something with local shipping for well under 100. I got the niles for @ 70$. I have the caps , cleaner , and any
other components I may need. Most of these AB amps use Sanken MT-100 pairs.
Edit - those arcams use hard to find "thermaltrak" OP devices. harder to find ?? boo Hoo...
OS