Don't know about current Woo Wee but in the past, apparently Woo had some issues about not having the appropriate safety resistors in the circuit, so I would go with the Stax.

Actually, the T1 is a hybrid, with solid state in all stages except the output. And the high levels of distortion in "tube amps" is as much myth as reality. In fact, the T1 is specified to have 0.02% distortion at 100V RMS which is a very loud level, and well below the consensus level of audible...

Thx for the update.

"Rather then buy a modded Stax amp the Phantom seems to deliver more power then any Stax amp ever made." Well, it's not quite clear. The iCan website says the Phantom can deliver 640V, however it doesn't say whether that is RMS or peak voltage. The Stax SRM727 is speced at 450V RMS at 1 kHz...

That really is NOT a good idea. The Topping LA90 is a power amplifier, which can put out up to about 30V RMS. The Kingsound M-03 is a portable stat amp (conceptually similar to a Stax SRM252), which is rated at an input level of 0.3V RMS. That is 100-fold lower voltage than what the LA90 can...

That should be adequate heat sinking. I am assuming you are using ceramic high voltage insulators and heat sink grease to attach the 10M90S. No other obvious thoughts.

Mouser is a reliable supplier - that's where I get my FETs. So there are a couple possibilities. The DN2540 regulates the current, so if the current is much higher than set, it likely means the DN2540 is blown. In theory the TO92 version should be enough, since it is the bottom FET, so it...

That is a subjective question so it depends a bit on what your sonic preferences are. I had a 727 with global feedback mod, and I preferred my modded T1, which sounded a bit smoother. I sold the 727, still have the T1. A couple friends who heard both also preferred the T1. The modded 727 does...

Looks like the JJs are equivalent to 6SN7GTA/GTB, which have higher voltage and power ratings than standard 6SN7 tubes. So they can be used in place of 6CG7 tubes as long as you have the correct adapters - depending on how tall they are with the adapter you may or may not be able to replace the...

Dominic Stritt is "firschi" on Head-Fi. The CCS mod is what I published in AudioXpress, July 2017. This substitutes a cascode MOSFET constant current source (AC impedance > 170 megohm) for the plate resistors that are used in all the Stax tube output amps (SRM-T1/T1S, T1w, 006 and can be...

Well, the Koss energizer has a bit higher bias voltage and power supply voltage, but it has pretty low current capability (according to Kevin Gilmore it only has 2 mA standing current per channel, while the portable Stax SRM-252 has about 4 mA/channel), not surprising as plastic doesn't make...

Perhaps that is because the SRM-1 never had XLR inputs to begin with. Prior to the SRM-T1S, all of the Stax amps had single ended RCA inputs only. Based on the schematic, the SRM-1 MkII has a diff amp topology input section (but used single-ended) so in theory it could be modified to take XLR...

I don't know if putting a 10 ohm resistor in parallel with the SRD-7 will fix your distortion problem or not, but it probably won't hurt. There are a few amps that need an output load to be stable, and their manufacturers often recommend that they not be powered up without a speaker load...

Well, it's not that complicated a circuit - 2 MOSFET's and 3 resistors plus a trim pot per current load - you need 4 current loads, which replace the plate resistors. I hard wired everything and attached it to a large single heatsink, but if that's too complicated, Kevin Gilmore has free...

Are you looking to do it yourself or are you looking for someone to do it for you? Where are you located?