johnsonwu

Responses from johnsonwu

Avalon Eidolon Vision
Slightly more efficient woofer.  Adjusted crossover.  But sound varies from one sample to another.  Be careful of oozing black goo behind woofer. Great w counterpoints :)   
Counterpoint Natural Progression Turn On Problems
What you are describing is too dramatic NP100s are extremely reliable and they are not that old the turn-on timer is triggered by a 555 timer that derives power from the 6.3v filament supply. pull out 1 of the 6sn7 tubes and see if it turns on ... 
Does anyone want a Counterpoint SA-20 chassis?
Contrary to urban folklore these things are very easy to fix and near equivalent Mosfets namely the IRF240 and IRFP240 in a different package are commonly available for cheap. No you don’t have to use Exicons or do a complete rebuild.   
Technics sr u 1000 ... vs Accuphase e-480
I’m sure some people here will start firing torpedoes but as far as I know this amp has a switching power supply that takes up less than 60W and I see no difference in heat or sound whether I plug it into the wall straight for through $70 Amazon s... 
Technics sr u 1000 ... vs Accuphase e-480
Loved the SU-R1000 enough to haul one back from Japan.  Saved enough to pay for air ticket and many many fancy meals.     
Technics SU-R1000
You cannot loop the pre out to an EQ and connected it to an input because the pre out of the R1000 is always connected to the output stage and there is NFB involved. That kind of slightly out of phase duplicate signal will indeed cause a loop and ... 
Technics SU-R1000
Hauled a unit back from Japan yesterday. most if not all dealers don’t have them in stock but can drop ship from Panasonic  Exchange rate too favorable to pass. Less than 6k USD brand spanking new hooked it up, calibrated LAPC and it’s been pla... 
Technics SU-R1000 - Good but not the king of switching amps
Amir pumps Topping products. Plain and simple.   
Review: VAC Phi Beta 110i
I have one I need to sell for JWaugh’s family.  sadly he passed away recently.   
amplifier longevity
@bigkidz I beg to differ. Keystone makes those white Q Covers with 4 holes, 1 hole, and no hole. The holes are not for ventilation but for a tech to use a probe to check rails voltage. There is no difference in temp disspation between the conventi... 
amplifier longevity
Re: the comment on Counterpoint Mosfets and heat It’s common practice for TO3 devices, mosfet or bipolar, to be covered by plastic covers.  They are there to prevent law suits when people get zapped by the + - rails voltages.  The heat of these de... 
Are Quicksilver power tube amps in the same league as VAC, VTL, BAT, ARC, ...?
@donvito The HD220 is entirely fixable. It’s loosely based on On Semi’s reference design for thermaltrak devices. The old production non DG designated output devices are End of Lifed but new ones are available on Mouser or Digikey. Unless your fri... 
The "Snake Oil" Trope
I love it when people try the Jedi mind trick “what? You mean… as a high end audiophile for 40 years you tell me you can’t hear this night and day difference?  You, among all the audiophiles?!”And all I need to to do is smile.   
Counterpoint SA-3000 Preamplifer
The SA3000 has a single tube line stage.  Each triode in that tube is cathode-driven with a JFET input stage and the plate goes to an ancient old OpAmp as buffer.The phono is also rather similar.  I would not spend much on it. 
Tube Preamp - What to buy?
@rbmaudio1 Counterpoint gear is not nearly as hard to service as urban myth has it and there is no need to "rebuild" with new boards all the time.  I have 2 of each of the popular models (SA100, SA20, NPS200, and NPS400) and I service them myself....