Babbelfish J PCBs

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one more thing-go to NP's and download one especially good article for me- "Discrete OP for us dummies"....just kidding ..."Diyopamp" is exact name of article...
there you'll find more about CCSs and gate controlling than I can write in a year... at least on my Engrish language.....


OK-2SJ176
 

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Thanks again Choky,

I will try the new circuit.

Is there an easier way to use a resister for a current source instead of the zener with the original Aleph 3 board? I have very efficient horn speakers 104 to 110 db/watt drivers and do occasionally notice random noises in my amp. I suspect now that it is the Zener? I was using 1uF bypass on the Zener.

Btw, I actually read the op amp article on my own before you posted that today. I have read it a couple of times, but must admit there is so much information that I still have not absorbed much of it.

I am happy to just follow a schematic yet alone building my own circuit design.

It will probably take me an evening or two to get your cicuit rebuilt to your new design. I will have to go to the local electronics store and buy some more resisters.

I sincerely hope the new j176 sounds better than the zvp3310a, because frankly I have not heard anything nicer than that yet with many different amps that I have listened to.

Regards, Bill
 
BillWW said:
Thanks again Choky,

I will try the new circuit.

Is there an easier way to use a resister for a current source instead of the zener with the original Aleph 3 board? I have very efficient horn speakers 104 to 110 db/watt drivers and do occasionally notice random noises in my amp. I suspect now that it is the Zener? I was using 1uF bypass on the Zener.



Regards, Bill


I have doubt's that random noise is from zenners;
must be some other culprit-bad solder joints, tired resistors -especially possible in so hot amps-as you said that you run it at full steam..
try it as simple you can,and when you decide which version you'll keep-tweak it further.
 
I'm going tomorrow to take pair of these :

:yinyang:
 

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Bill's Aleph 3 converted to Aleph J

Choky and jh6you and all,

I have been selfishly listening to the converted Aleph 3 to Aleph J and have not posted the results for the past day. I got it up and running late last night.

It sounds different than my previously zvp3310a version. I would say it is more musical than even this previous version. I took Choky's advice and put the IRF9610 for current source. That seems to give it more bass, so perhaps the other zvp3310a was not offering enough current?

I ended up using a silver mica 5 pF for the 220K ohm feedback resister, which seemed to be the best balance.

On the 4.75K ohm resister near the ground that is below the zener regulator, I also placed a 10K ohm pot and adjusted that also. It seems to give better clarity at around 4.64K ohm in my current set up. I measured about close to under 18 mA on the current source with the new parameters that Choky posted earlier.

I will be ready now for the Pass Shoot out in Salt Lake City in a month!!!

It sounds very nice. I do not know yet how to describe it, because I have not been able to listen to it long enough, but it seems to be very delicate on intruments with a lot of clarity and might even be smoother than my zvp3310a version.

So, am I the first person on this forum to convert their Aleph 3 to J with a lot of sucess?😀
 
Re: Bill's Aleph 3 converted to Aleph J

BillWW said:


So, am I the first person on this forum to convert their Aleph 3 to J with a lot of sucess?😀

nope;

you are second;
I converted my non-existent Aleph 3 to Babelfish J :devilr:

as I said-maybe NP have some trick in bag ,especially to decrease dissipation in these funny little Jfets ; (maybe splitted and/or additional source resistors,maybe few zenners in sources..)
I think of some of possible tricks,but I didn't tried . maybe because I'm used to burn risky watts in my toobz :devilr:

.....so what we have may be just approximation;
but -I dare to say ,pretty good one.

I'm really glad for ya 😉
keep us informed about next shoot out
 
I forget to say in spks related posts- I give 7 pcs of GEC KT66 plus some smaller goodies for them;
I don't need KT66 ,but these spks are pricelles

anyway-mentioned RCA LC1A spks + cabs are for trade in this moment...price- DIRT CHEAP!
but-hey-they are in Serbia....Belgrade....
anyway,if somebody is interested in these antique beauties ,just PM Zoran ....here on DIY.....

I'm too poor 🙁
 
Aleph 3 conversion

Well, with extensive listening tests, I have found this J conversion sounds 5 to 10 times better than even my zvp3310a version. It is so 3d holographic compared to the previous version. The soundstage is much wider too. The bass is much stronger too most likely due to the irf9610 as a current source.

Thanks again Choky. It turned out very well!!! I can't wait for the next shoot out.

One thing on your schematic, you showed the 220uF "gekoppelt" capacitor missing on your aleph 3 conversion. I could not get mine to work with that missing. Was that an error? I had to leave my dc coupled capacitor in order for the amp to work right. If this is removed, I noticed my DC offset went really high --not safe for speakers. Would it sound better with this capacitor removed and if so how do I get the DC offset lowered safely. What would be the sound differences with these two styles?

Also, another question about jfets. Is it better to have lower input capacitance?

I noticed the j176 that I purchased was a lot lower than the 2sj109 that everyone is using, so just was curious if that would make this a better jfet for linearity? Maybe it would sound better than this other 2sj109? I believe the 2sj109 has 95 pF, while the j176 had either 8 or 30. I could not tell which one was the input capacitance, but either one is still a lot less than 95?

In otherwards, could my Aleph J with j176 be more linear than the 2sj109 and therefore better sounding than everyone elses? Btw, my Aleph 3 draws 550 Watts versus 200 Watts for the stock Aleph 3 It has to have fans to keep the temperature down below 55 Celsius. The Aleph J seems to run a few degrees cooler and still sounds nicer than the previous Aleph 3. :clown:

Regads, Bill
 
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