Hi I am looking for experiences where people got medium cost amps modded from their tech engineer (upgraded caps etc) and these beat unmodded branded big name amps that cost a few thousand more.
Looking for amps with 200w plus that double down, preferable class A SS.
I have a stereo Kismet amp in a Stratos case, Klaus will do many upgrades himself such as WBT RCAs, binding posts, power trafos and caps. Further upgrades could be done in input caps and internal wiring, Klaus uses his Groeningberg wire for upgraded models but it's not much of an upgrade imo, overly heavy gauge stranded copper wire is not my idea of top notch signal wiring.
These amps won a lot of awards and I think you'll have to spend much more to beat his factory-direct pricing. Further mods are straightforward, it's not a very complicated amp.
Yes, Klaus has connections with Symphonic Line and can sell you their amps too. I think his amps are based on the SL amps as well, basically a factory-direct high-value version.
For cheaper options I'd also consider Nord's NC500 amps and even Crown XLS 2502... Nord would probably do whatever upgrades you like and the Crowns are excellent but require some upgrades in connectors to minimize harshness.
I have owned and/or heard 3 different color boards and a plethora of varying upgrades from Klauss and yes, with each tier comes more power, clarity, finesse, headroom, etc.. Please note that you want to keep these amplifiers on ALL of the time. Once you unplug them or turn them off, even after 3 or 4 months of constant break in, IME they will take 3 days to get back to where you were once they cool down. BTW, I believe the first 15 watts are class A before it switches to class A/B.
I have modified my now 25 year old 765 wpc@8 Ohm Crown Macro Reference amp over the years and am quite pleased with it. Stock, it had a noise measurement of -122db, which to this day is excellent for any power amp. Mods include: replacement of the 7815/7915 voltage regulators for the front end with Sparkos Labs discrete ones (as used in Nord UP buffers), bypassing the main power rails with large value multicap metalized polypropylene films directly on the output devices, shorted one electrolytic cap in the signal path and replaced the other with a Black Gate N with polypro bypass, and added some other film bypasses on the opamp power rails. My next mod is to upgrade the stock film cap in the global NFB loop for high frequencies with a polystyrene or teflon because part nonlinearities in negative feedback loops get amplified.
Unlike most Crown amps, this one and studio reference 1 and 2 amps have a linear power supply and run class AB, biased at about 90 watts idle power consumption.