The amplifier is not assembled yet, so its early to make objective judgements. But, ofcourse I listened to it a lot in its scattered state and with cheap pots and with preliminary wiring. Computer with O-DAC was mainly used as a source. May be the O-DAC is not top of the class, but it certainly is far better than FM tuner. Music was Mozart violin and piano concertos, Terauchi electric guitar, Weber rock opera JC Superstar. First of all bass on the speakers had to be lowered (they feature regulated crossover). Because the bass is very strongly expressed. After that the sound became pleasant and detailed. It has the property of being not fatiguing on a long term. I heard these AR10pi speakers driven by a couple of my fathers Marantz amps (the 80s models, don't remember which) and lately by a LM1875 chipamp (not bad). Compared to those My_Ref FE is distinctly better. Music appears well balanced and articulated. That is, instruments are not obscured one by the other. Merely by refocusing attention one can distinguish the particular line. The challenging string instruments are very authentic. I look forward to examine the sound of egyptian horns in the Aida with this amplifier. Never heard them properly reproduced. These are my impressions for the moment. A lot more listening is planned and I will continue to share my impressions.
Sorry, I don't know...
Interesting...
If this is a problem it can be addressed changing C13.
A NOS K71-4 (which is a bit bass shy but really refined) may bettter suit you needs.
The MP915s on the regulator have a big role in bass response, you can swap them with metalfilm resistors to lower it if C13 swap it's not enough.
Thanks for sharing, I'll read with interest next posts.
Dario, thanks for valuable advice! Plans are to mount the scattered parts to an open chassis, and after that to start tuning. Regarding the bass issue, old AR speakers may be responsible for that. Large drivers had torn rubber replaced few years ago. And, the drivers being not one of the standard sizes, the repair went not without compromises. They may reproduce deep bass not very well (for instance, contrabass in Mozart's 3rd violin concerto). At the lower bass settings of crossover they work nicely with My_Ref now. Also the source may not have been perfect. I will listen for some time and try variants of C13.
I'm sorry to say that, just like Dario, I don't know the answer. I suspect that you might give up some sound quality or hum on the headphone side because you may be introducing a potential ground loop by combining the grounds. If you keep the switches and headphone components close to the audio ground from your source, it might be OK.
I don't think you would hurt the amps by trying it. Why not just try it as an experiment before building the enclosure? We would love to hear about it.
I had several AR speakers "back in the day" and they were all acoustic suspension. I'm assuming if yours are some of those great classics - yours are also. Though considered the "Cadillac" of sound production by many, as I remember their best reviews had to do with clarity over coloration. The last few speakers I've built are all bass reflex, as driver technology for controlling cone movement has really improved. My preference has kept me there and I'm not claiming it to be a top choice for everyone.
I'm simply suggesting if you don't own any, try to find a pair of good quality BRs somewhere in your auditions. I suspect much of the mid warmth the FEs are capable of might be masked by the "clean" nature of acoustic suspension cabinets. Just Sayin.....
I'm simply suggesting if you don't own any, try to find a pair of good quality BRs somewhere in your auditions. I suspect much of the mid warmth the FEs are capable of might be masked by the "clean" nature of acoustic suspension cabinets. Just Sayin.....
Yes, I'll do it in the coming week and report. Thank you.
I'm simply suggesting if you don't own any, try to find a pair of good quality BRs somewhere in your auditions. I suspect much of the mid warmth the FEs are capable of might be masked by the "clean" nature of acoustic suspension cabinets. Just Sayin.....
I appreciate and will follow your advice.
Allright.
I have tested one channel.
It is only one speaker but simple thing- soundstage from monophonic sound was already promising.
All and every detail of the music qualitative evaluation was 10 light years ahead of the amp I have now.
Will wait for another board to be done and will give my impressions then.
I can imagine break in of all parts is going to take place so sound should get better after that also.
Bass is good. 3D sound and separation of instruments great.
The only thing - I must be liking more rolled off high end than I have now- but it is the domain of k71-4 cap in b1 (together with nichicon electrolytic which adds some highs on top). Because I am changing to another passive pre with buffered dac - things will improve.
Plus, again- break in...
And yes- this amp is unforgiving to bad mastering and SQ.
Sincerely yours
Ivan
I have tested one channel.
It is only one speaker but simple thing- soundstage from monophonic sound was already promising.
All and every detail of the music qualitative evaluation was 10 light years ahead of the amp I have now.
Will wait for another board to be done and will give my impressions then.
I can imagine break in of all parts is going to take place so sound should get better after that also.
Bass is good. 3D sound and separation of instruments great.
The only thing - I must be liking more rolled off high end than I have now- but it is the domain of k71-4 cap in b1 (together with nichicon electrolytic which adds some highs on top). Because I am changing to another passive pre with buffered dac - things will improve.
Plus, again- break in...
And yes- this amp is unforgiving to bad mastering and SQ.
Sincerely yours
Ivan
I definitely do not expect amp work on full capacity outright.
I like multilevel bass, snares slam nicely over the drums. Let's wait till the second board completed.
Hope to finish it before holidays, it is 2 weeks deadline.
P.s: see the group buy for all in one passive pre. I thinj it is a good combo to be
I like multilevel bass, snares slam nicely over the drums. Let's wait till the second board completed.
Hope to finish it before holidays, it is 2 weeks deadline.
P.s: see the group buy for all in one passive pre. I thinj it is a good combo to be
Sorry posted it from the phone ,
this should be correct:
http://www.diyaudio.com/forums/group-buys/237302-versatile-comfortable-passive-pre-amp-16.html
this should be correct:
http://www.diyaudio.com/forums/group-buys/237302-versatile-comfortable-passive-pre-amp-16.html
Headphones and My_Ref FE
In fact some resources can be found on use of headphones with integrated amplifiers. For instance Headphone Adaptor for Power Amplifiers . Today I made a temporary PTP adapter shown on the scheme below and connected it to replace the speakers. Sennheiser HD600 phones were plugged into the adapter. The resulting sound is great. And to my satisfaction it is very similar to the sound produced by the speakers. Also no hum or other disturbances. Still, I have to focus attention on the fact that the two blocks of the amplifier are connected only at one point, that is at the ground of the headphone jack. Hence, there are no ground loops. I am happy with successfull test and will now incorporate headphone jack into the chassis (using a 10A 4 ON-ON switch or relays).
In fact some resources can be found on use of headphones with integrated amplifiers. For instance Headphone Adaptor for Power Amplifiers . Today I made a temporary PTP adapter shown on the scheme below and connected it to replace the speakers. Sennheiser HD600 phones were plugged into the adapter. The resulting sound is great. And to my satisfaction it is very similar to the sound produced by the speakers. Also no hum or other disturbances. Still, I have to focus attention on the fact that the two blocks of the amplifier are connected only at one point, that is at the ground of the headphone jack. Hence, there are no ground loops. I am happy with successfull test and will now incorporate headphone jack into the chassis (using a 10A 4 ON-ON switch or relays).
Attachments
Here is the information I received from Parts Express. The quote was for lots of twelve.
1501526 1 uF $36.77 ea
1501527 1.2 uF $37.57 ea
1501528 1.5 uF $39.38 ea
They said the shipping from Germany would be based on weight. PE has minimum $7 shipping charge for small items. Orders over $100 are shipped free. (Good time to buy drivers for those new speakers you want to build)
So it looks like a portion of the shipping costs could be eliminated if 12 people buy in a special order. They have received several requests and are still considering if they can make the True Coppers a stock item. Maybe a few more calls might convince them to do so.
It does appear that accepting Ivan's offer would be a better deal if there is not enough interest for a group buy. Sounds like Audyn knows they have a star product and aren't willing to make much of an adjustment. I guess that's the way a company stays in business.
1501526 1 uF $36.77 ea
1501527 1.2 uF $37.57 ea
1501528 1.5 uF $39.38 ea
They said the shipping from Germany would be based on weight. PE has minimum $7 shipping charge for small items. Orders over $100 are shipped free. (Good time to buy drivers for those new speakers you want to build
) So it looks like a portion of the shipping costs could be eliminated if 12 people buy in a special order. They have received several requests and are still considering if they can make the True Coppers a stock item. Maybe a few more calls might convince them to do so.
It does appear that accepting Ivan's offer would be a better deal if there is not enough interest for a group buy. Sounds like Audyn knows they have a star product and aren't willing to make much of an adjustment. I guess that's the way a company stays in business.