Doshi Jhor 90W monoblocks


Has anyone had experience with a Dohsi John 90W amp? I am looking to use them with my SonUs Faber Olympia IIIs. Not much information on the web. 

Basic Specs
EL34 Pentode output tubes – 90 watts per channel
Input Impedance: 75k ohms
Sensitivity: .775v rms for full power
Feedback: 22db
Output Impedance: 4 ohms
Output Power: 90 w
 
Here are the specs for my speakers
FREQUENCY RESPONSE
35 Hz – 30.000 Hz, tuning port included.
SENSITIVITY
90 dB SPL (2.83 V/1m). NOMINAL
IMPEDANCE
4 ohm.
SUGGESTED AMPLIFIER POWER OUTPUT
50W – 300W, without clipping.
LONG-TERM MAXIMUM INPUT VOLTAGE (IEC-268-5)
22V rms.


Room 13 X 15 feet 195 sq feet
ceiling 7 feet
Total volume = 1365 feet



Source:     MiniMac 2014 3.0GHZ I7 16 GB 4TB SSD as NAS
Software:     Roon, Tidal
DAC:       PS Audio Directstream
PreAmp:     As phono stage Moving Coil Anthem Pre 1
PreAmp:   Doge Clarity preamp used as line stage and MM phono stage
Turntable:     VPI Aries Limited Edition
Speakers:   SonUs Faber Olympia III
Sub:       SVS SB13-Ultra
Power:     Furman Elite-15 PFi
Cart:             Denon MC DL-103R
SUT:       Bob’s Devices SKY

I am a newbie. Any advice would be appreciated. Thanks!

chazark123

 I have Sonus Faber Elipsa SE speakers which are driven by an Audio Research Ref 110 with KT120 tubes. Audio Research is an excellent match with Sonus Faber.  I would choose an amp that uses 6550/KT120/KT150 tubes and at least 100 watts per channel. If you don't have enough power the bass can sound a bit sloppy. 

 The preamp has more impact on the sound than the amp. But it is all about synergy. You want to choose components that work well together.


If I am not mistaken, most if not all audio research amps only have balanced connections. I would need to use some type of XLR to RCA converter. Would such a converter have a negative sonic impact?

 Most Audio Research components today are fully balanced. This was not always the case in the past. You can use a converter and I thin there would be minimal impact. I have a pair of little Canare ends that convert from balanced to single ended somewhere. I have used them in a pinch. But if you later upgraded to a fully balanced preamp such as a Ref 3 or Ref 5se,  It will have a positive affect. There is a synergy with both an Audio Research amp and preamp. Even older Audio Research Ref preamps are truly excellent. 

 I would come up with a long term plan and work toward it.  You can have excellent sounding components but if they don't work well together the system won't sound great. Synergy between components is very important.  The Sonus Faber Olympica III are very musical speakers. The better the the electronics that feed them, the better they will sound. 


I have been using my Doshi Jhor amps (original versions) and Alaap full function preamp with Amati Futuras for the last 1.5 years. I love the combination. The Doshi gear were purchased to go with my Sashas and that was a great system. But the Doshi and Sonus Faber combination is even better. Before Doshi, I had Lamm and Audio Research amps and preamps.   My room is 17 X 34 X 9, and the amps drive the speakers very well in the large space.

If you want another opinion, you might call Larry Marcus at Paragon Sight & Sound. He sells Doshi and Audio Research, and also sells Sonus Faber and Wilson. He’ll give you a straight answer.

One more thing, before I bought my Sonus Faber speakers, I called Nick Doshi to ask him about what speakers he feels are excellent with his amps and he recommended Wilson (of course), Harbeth, and Sonus Faber.

If you go with the Doshi amps, I’ve had great success with Telefunken EL34 output tubes. If you want more information or want to talk, pm me or send me a separate email at daveneumann01@gmail.com

Regards,
Dave
If you want to try tubes, I would look at Atma-Sphere.
But, if you want to try the Doshi, then you could get some rca-xlr convertors from Jensen for about $300. I spoke with Ralph (Atma-Sphere) and he said they shouldn't do much to the sound- I was thinking of using them when I bought his amps). 
I would then look for a pair of Zero Autoformers to help with the 4 ohm response of your speakers.
Hopefully, Ralph will see this post and give you the most accurate information.
Bob