I don't think they have any reason to do a review on a non production product.
This P-3 measures better with higher gain.
I adjusted the value or R22 down to 100R and the jumper in place the Gain went down to 46dB the entire series of Harmonic Distortions showed up in the FFT Plot.
With R22 at the specified 220R and the jumper in place the Gain was 50dB with no HD's above the FFT Plot noise floor.
If you want 40dB of gain tor a MM cartridge I do not see any HD's in the noise floor of the Bugle RIAA pre-amp. I used the same 7815 and 7915 regulated supplies as used in the P-3, plus opa1656 op-amps.
Thanks DT
Thank you! That's the kind of feedback I was hoping for, of course as it pertains to the high gain side. Intuition says lowering R9 would have benefits, but what are the potential downsides?
R22 is in parallel with R9 with the jumper in place. Paralleling R9 does lower the overall resistance in the loop.
DT
Yes it must be, the PSU 0Vs are connected to the + pos of the bridge. The AC's are strapped to the chassis along with the IEC safety earth to chassis.
Totally silent, very impressive.
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Been doing some more 'auditioning' of PSU's. The Kit PSU's I was using in Duel Mono config don't belong to me (built some more P3's for others) so I had to use my own, which was originally 30,000uF 63v. So Ive now swapped those out for some 4700uF 25v with Nichicon (so called) Audio Grade CAPs4700uF 25v in the CRCRC config, the rectifiers are SMD's on the under side of the board.
and opamps.... These OP27's singles, sound really good, yes I'm pushing them at 15v (these are at least 20 years old should be 12v new variant will run to 22v) but back in the day used these in a few CDPlayers with great results. Early days though....
There seems to be a benefit to running two single opamps.
and opamps.... These OP27's singles, sound really good, yes I'm pushing them at 15v (these are at least 20 years old should be 12v new variant will run to 22v) but back in the day used these in a few CDPlayers with great results. Early days though....
There seems to be a benefit to running two single opamps.
Agree, but failing that, you can gather some data from those of us that have compared the Pearl 3 with our current/past phono pres.
Have two vinyl systems, both with VPI Primes, and one used Slee's Accession MC and the other, the E,A.R. 834 tube pre (yes, it's the Chinese clone version....).
As stated above, the Pearl 3 blows them both out of the water. While the Slee is somewhat similar in terms of accurate SS amplification, it just isn't as dynamic, quiet, and timbrally correct as the Pearl. Most telling are transients: they explode out of the Pearl but are just very good with the Slee.
The 834 is a completely different kind of device -- it has plenty of that tube warmth but sounds sloppy by cf. to the Pearl.
So others on this thread might add their comparative information to help amplitude flesh out a more full picture as to how the Pearl would compare with retail machines in a shootout. Would love to hear from someone who has heard a phono pre significantly better than the Pearl.
The highest high-end, "nosebleed solution" second-chassis power supply for Pearl3, turns out to be UDP3 (link to thread).
Of course, a complete madman who believes "if some is good then more is better" might decide to gild the lily even further. Such a person might hire a circuit designer to engineer an additional power supply in yet a third chassis, and have it deliver an extremely heavily filtered ±31.1VDC to the input of UDP3. Thus: ACmains ---> Box3 AC-to-DC power supply ---> Box2 UDP3 ---> Box1 Pearl3.
Your circuit designer can explain why it is (or is not) possible to apply ±31.1VDC instead of a dual secondary 2x22VAC transformer, to the UDP3 inputs. They'll probably charge you for at least 1 hour of consulting time, to explain how it works and to answer your follow up questions.
Of course, a complete madman who believes "if some is good then more is better" might decide to gild the lily even further. Such a person might hire a circuit designer to engineer an additional power supply in yet a third chassis, and have it deliver an extremely heavily filtered ±31.1VDC to the input of UDP3. Thus: ACmains ---> Box3 AC-to-DC power supply ---> Box2 UDP3 ---> Box1 Pearl3.
Your circuit designer can explain why it is (or is not) possible to apply ±31.1VDC instead of a dual secondary 2x22VAC transformer, to the UDP3 inputs. They'll probably charge you for at least 1 hour of consulting time, to explain how it works and to answer your follow up questions.
amplidude.
"Getting names right is the “bedrock” measure of accuracy in journalism." -- Kathy English, Public Editor, Toronto Star
Of course she didn't have know-it-all Android "fixing" spelling for her.
My Pearl is working well except for the front panel LEDs, which I managed to reverse my wiring at the LED legs,. Before I replace them, I am concerned with the voltage that I read, 20v on both sides?
Just turn them around. Installing it backwards doesn't damage an LED, it merely won‘t light.
Should work well as long as you keep the wires short and in a quiet portion of the box. I've used a rotary switch in another phono build. No problem.
I remember that. Wasn't it a no gain deal using video buffers of some sort? "Aunt Corey's buffer" or something like that?
yup. a buffered passive preamp. can't recall the op amps.
my point was that there can be and has been a productive intersection between diy and mainstream audio.
and the Audiophiliac did a comparison very like what was asked for... but for a different Pass design down the audio chain.
germane I thought...
my point was that there can be and has been a productive intersection between diy and mainstream audio.
and the Audiophiliac did a comparison very like what was asked for... but for a different Pass design down the audio chain.
germane I thought...