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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
11 responses Add your response
chazark123 OP
5 posts
 
Everyone,
Sorry for the delay in responding, I have been traveling. Thank you for your excellent suggestions. I did have an opportunity to audition the Doshi Jhor with a set of Sonus Faber Olympia III speakers. On one hand, I found this to be an excellent amp and clearly well constructed/ engineered with superb sound staging and an impressive sound floor better than what I am currently using. To my surprise I found the sound of this tube amp "fuzzier" than I thought it would be especially with the mids.

I do not think this is inherent to the amp, rather simple the difference between a tube vs solid state. I am currently using a tube preamp which I suspect along with my legacy Acurus A 150 SS is giving me the warmth I am looking for.

But... you know the drill, always looking for something to tweak and improve.  I hope to audition some ARCs in the near future.
lak's avatar
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lak
4,619 posts
 
I was going to suggest what Dave said; phone Larry Marcus at Paragon Sound. Larry could answer your questions and give honest comparisons to other amps.
gdnrbob
4,444 posts
 
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
tricon_dave
96 posts
 
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
lostbears's avatar
lostbears
538 posts
 

 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. 


chazark123 OP
5 posts
 
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?
lostbears's avatar
lostbears
538 posts
 

 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.


chazark123 OP
5 posts
 
I am looking at a used Johr and would like to try tubes. My preamp only has RCA unbalanced inputs. This would be my first tube amp with a speaker known to be hard to drive at 4ohms
joecasey
484 posts
 
Doshi Johr is voiced for Wilson Sasha's and bit on dark side so IMO not best match for SF.   For tube amps, checkout ARC.
goldprintaudio's avatar
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goldprintaudio
502 posts
 
I've never read anything that was less then positive when it comes to Doshi, so I imagine the Johr's are very nice amps.

Are you specifically looking for an amp with EL34 output tubes?  Or any specific reason you are considering the Doshi's?
audiotroy's avatar
audiotroy
3,778 posts
 

I have not heard the Doshi however, I have heard many people whom I respect say that the Doshi stuff is excellent. 

The biggest issue is that a company like Doshi has very few dealers throughout the country so they are hard to demo.

Other great salwarts like ARC and CJ might also interest you.

We have a demo pair of CJ Art amplifiers which use 6650 or KT 120 which are punchy tubes with great bass.

The  EL 34 tube is known for musicallity rather than bass omph so it will also depend on how you want to use your system. 

If you are new to tube amplifiers PM us we have a lot of experience with many different brands and can give you a low down on what you might want to expect.

Dave and Troy
Audio Doctor NJ
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