Jisbos Worthwhile upgrade ?

[regal]

My first attempt with the jisbos failed, I have arthritis and can't build like I could a few years ago, but am sure I could pull it off if it was a nice upgrade. Is the Jisbos a worhwhile upgrade to the SOHA. I use AKG Sextetts (600 ohm).

As a frame of reference I tend to favor my SOHA vs my Millet+dB, but it is very very close. I did find the dB to be a major improvement to stacked Buff634's on the Millett.

I really haven't seen any raving reviews of the Jisbos upgrade like I did when the dB's were developed for the Millett, that's why I ask.

 

[akione]

I'm afraid I can't answer your question about how good the Jisbos sound, but I just wanted to encourage you not to give up with the DIY.
I too have Arthritis, in both hands, but with a little patience and perseverence I was able to complete a Beta22.
It's really just casework which I have a problem with.

The Jisbos should be fairly straightforward, I would have thought.

 

[FallenAngel]

Yep, should very very worthwhile.

 

[regal]

I finished the Jisbos today. It is a worthwhile upgrade. This SOHA+Jisbos is very different than my Millet+dB, they compliment each other nicely. I used the 3422/1359 output transistors.

What I like about the Jisbos+SOHA is the center imaging doesn't get pushed away like on the Millet. The Soha seems faster as well. But the Millet is smoother.

I'm using a GE5963 tube, overall this is a better amp than my Millet+DB, much more power.

I wonder how the SOHA+JISBOS compares to a Millet-Max or Bijou.

 

[fortney]

The JISBOS makes a fine stand-alone current amp also.
That is the way I use mine and it is my favorite among simple amps I have built.
I may build a number of them for Christmas or birthday gifts.
I guess I am easily entertained: I enjoy adjusting the bias and DC offset on these units.

F

 

[regal]

I am amazed at how much closer the center of the sound-stage is with this amp vs my Millet/DB.

 

[regal]

I noticed with my 600 ohm AKG Sextetts that this amp is incredible, blows away the Millett+DB, but with my AKG271s (50 ohm) its only slightly better. There is a hint of sharpness in the upper mids with the 50 ohm phones. I have the Jisbos biased to 30 mA, may need to go higher.

I used the alternative wiring scheme which reduced the gain to 8, I also upped the coupling cap to a 2uF Solen (that's what I had on hand.)

With the 600 ohm AKG's this combo is breath-taking. It is completly a different league than the Millett. I am really surprised that there aren't any reviews about this combo. It is almost shocking how good this $120 amp is.

 

[dBel84]

I can well believe your favourable impressions, I no longer own a SOHA but have a hybrid which uses the 12AU7 tubes and a discrete output stage and it sounds fantastic. One recommendation, try and source an 8416 tube (this is a 12.6V heater version of the 6922 ); I find this combination superb. I think this is because the 6922 is happier at lower plate voltages. (however, my amp runs higher B+). Just as an aside , I always did find the SOHA surprisingly good everytime I compared it to other amps that I had built, often costing significantly more and most definitely more complex than the SOHA. glad you are finding it sounds even better with the output buffer..dB

 

[regal]

Now that the tube has burned in the upper mid harshness has settled down. I think the SOHA+Jisbos is sort of a secret here, this is a very fine amp.