Penny & Giles: Good or not for HiFi?

[tiefbassuebertr]

Many Levinson, JC-80, etc

Hi John, happy New Year also from me. And thank you very much for this advice.
Mean you this dual mono devices?
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Hi John,

Happy New Year to you.

I'm still running a pair of Levinson ML-2's and I was wondering how much of your knowledge/intellect is there in those designs?
My Krell technician (former Goldmund engineer) prefers the ML-2's over the successors the No. 20 and 20.5. I never heard those latter ones so I can't concur.
Are the ML-2's mainly your brainchilds?

To tiefbassuebertr:
Congratulations with your nice MF preamp.
Did not know the English made such expensive gear.

Unfortunately that is not the preamp part from my own setup. I found the pictures on the web by chance.
Obviously there is no high circulation of this model.

 

[RobertS61]

Those are the P+G sliders

 

[thesun]

That's a surprise.
The Krell would have used it in its premium line even more I suppose.

Never liked the TKD's with there flimsy soldering lugs.
Just bought a Coherence One Series II so I'm back in P+G territory again with three of them lined up behind a faceplate.

Penny & Giles (Position Measurement and Control Hardware - Penny + Giles) are best known for their line of "industrial" controllers and linear faders. They also make a rotary fader (model RF15) which is the volume control you are asking about. It is built like the proverbial tank and looks like it would withstand a nuclear blast. I used these in my Deluxe Line Drive series of passive preamps back in the '80's, but gave them up after I found a part I liked better - the TKD conductive plastic pot. Like Penny & Giles, TKD makes a line of industrial-grade linear faders, but they also make rotary faders (potentiometers) and stepped-attenuators. These are excellent volume controls, but the stepped parts have gotten extremely expensive. The conductive plastic pot (CP2511) can be had from Michael Percy Audio (Michael Percy Audio Ordering Information) for $62.50, while the stepped-attenuator goes for around $250.

Best regards,

Steve McCormack
SMc Audio

 

[Earthfield]

Best potentiometers without a doubt? Penny & Giles Model No. D460355/C recently resurrected. Heavier silver oxide and better machined tracks. "In the initial refit of a KRS-2, the Pot by Penny and Giles D19992 was found to be unbalanced between L+R at very low volumes, which was incredibly frustrating having waited six months for it. It turns out that the silver oxide manufacture was changed in the middle of the recession. After long discussion with Penny & Giles, an older type with higher tolerances was resurrected and produced... another three months... however the results are world class, Its model/ type D460355/C and the best available. Max differential between left and right tracks is specified at a maximum of 0.5dB, that -as it turns out- was the critical figure! The D19992 of the RF15 style was a max deviation of 2.5dB." TKD good but flimsy. The Model No. D460355/C is the best potentiometer out there, that is unless you go to rotary fixed resistors....and some other exotica that may well out live my grandchildren! If you do a google search for KRS-2 and find my posts on pinkfish media, an expansive conversation with penny and giles seeking the best potentiometer that they made for audio is peppered throughout that post, it took months and months to find this out. My ears concur.

 

[ShaneF]

Does anyone know the impedance of the PandG in the Aragon Aurum? would a stepped attenuator be an upgrade to this? If so, what would you suggest?

 

[rwwear]

Best potentiometers without a doubt? Penny & Giles Model No. D460355/C recently resurrected. Heavier silver oxide and better machined tracks. "In the initial refit of a KRS-2, the Pot by Penny and Giles D19992 was found to be unbalanced between L+R at very low volumes, which was incredibly frustrating having waited six months for it. It turns out that the silver oxide manufacture was changed in the middle of the recession. After long discussion with Penny & Giles, an older type with higher tolerances was resurrected and produced... another three months... however the results are world class, Its model/ type D460355/C and the best available. Max differential between left and right tracks is specified at a maximum of 0.5dB, that -as it turns out- was the critical figure! The D19992 of the RF15 style was a max deviation of 2.5dB." TKD good but flimsy. The Model No. D460355/C is the best potentiometer out there, that is unless you go to rotary fixed resistors....and some other exotica that may well out live my grandchildren! If you do a google search for KRS-2 and find my posts on pinkfish media, an expansive conversation with penny and giles seeking the best potentiometer that they made for audio is peppered throughout that post, it took months and months to find this out. My ears concur.

Beautiful KRS 2 and great job. I read your post on PFM. I have a KBL just back from Krell with a complete PS rebuild. I'm thinking about replacing the old VC with a motorized model. Any suggestions? Thanks.

 

[tiefbassuebertr]

Penny & Giles Rotary Fader RF15 Series/RF15 Style - how many variations ?

Best potentiometers without a doubt? Penny & Giles Model No. D460355/C recently resurrected. Heavier silver oxide and better machined tracks. "In the initial refit of a KRS-2, the Pot by Penny and Giles D19992 was found to be unbalanced between L+R at very low volumes, which was incredibly frustrating having waited six months for it. It turns out that the silver oxide manufacture was changed in the middle of the recession. After long discussion with Penny & Giles, an older type with higher tolerances was resurrected and produced... another three months... however the results are world class, Its model/ type D460355/C and the best available. Max differential between left and right tracks is specified at a maximum of 0.5dB, that -as it turns out- was the critical figure! The D19992 of the RF15 style was a max deviation of 2.5dB." TKD good but flimsy. The Model No. D460355/C is the best potentiometer out there, that is unless you go to rotary fixed resistors....and some other exotica that may well out live my grandchildren! If you do a google search for KRS-2 and find my posts on pinkfish media, an expansive conversation with penny and giles seeking the best potentiometer that they made for audio is peppered throughout that post, it took months and months to find this out. My ears concur.

good information - thank you.
There are a lot of versions from the RF15 series. Until now I have discover versions as follow:

A: Single Channel/Mono Potentiometer:
1) D23017/2 for JRDG C1 Balance - go to
Jeff Rowland Coherence 1 - Schematic for the Modules wanted
and
?? mimesis PH3 ?? - ????????? - ???[Tubebbs]???? ??|??|???|??|????|????|????|???|???|???|??|?? (scroll down)
2) D22667 (RF15/2/1304) for Mark Levinson's ML6B - go to
review33.com - 影音天地

B: Dual Channel/Stereo Potentiometer
1) D460335 best choise according your description under
Krell KRS-2 | pink fish media
2) D460235 (RF15/2) for Mark Levinson's ML7
MARK LEVINSON ML7 POT
3) D460343 (RF15/2/20K/AX)
https://www.yoycart.com/Product/524726715273/
4) D23317 (RF15/2/C/A) for Horch 1.2 (Preamp from German Brand Horch Elektroakustik)
5) D21999/2 for various preamp models
6) D21999 (RF15/2/D/A) for Marenius DAC-S2 - go to
https://www.marenius.se/pdf/dac_s2_datasheet_2s.pdf
7) RF15 versions without additional numbers

currently website don't have a download area for datasheets
https://www.cw-industrialgroup.com/Products/Legacy-Products/Faders/Rotary-Fader-RF15

From where I can download this ? Which of the mentioned versions are oil filled ?

Thank you for advices.

more URLs
https://www.audiocircle.com/index.php?topic=101039.0

 

[tiefbassuebertr]

Images of RF15 Variations (Dual Channel/Stereo Potentiometer)

Images of "B" from my previous post

 

[tiefbassuebertr]

RF15, D21999/2

images of the versions with blue sticker on back plate

 

[tiefbassuebertr]

Older RF15 Versions

Early Versions

 

[tiefbassuebertr]

Even a D/A Converter with Penny & Giles Potentiometer is available

This brand I haven't heard before:
MARENIUS | Startsida

 

[Handel]

Hello all,

I have also Penny&Giles RF15 in my ML26 preamp.
The this volume control has started to have noise when turning. Is there something I can do for the pot or just buy new? I have tried to rotate it multiple times back and forth but it does not help. Is there any maintenance that I can do?
Thanks.

 

[RobertS61]

Maybe DC problem?

 

[RobertS61]

Or try to contact them:
Multi-Channel Rotary Potentiometer Fader
| Curtiss-Wright

I've had Levinson No.26, ML-7, ML-7A, ML-10A, ML-6A, JRDG Coherence One, Krell KRS-2 and Krell KRC, all with the RF-15 rotary faders and never experienced any problems with them but I was probably lucky ;-)

 

[Handel]

Hello Robert,
Thanks for the info. I will contact them.

 

[tiefbassuebertr]

Maybe DC problem?

yes, easy to find out by introduce MKP-caps (0,47-1uF).
Consequence is an unwanted high pass character.
But this doesn't matter to find out the reason for the unwanted scratching effect.
Is with the use of the mentioned capacitors to observe the absence of noise while rotate, unwanted DC is the reason.

 

[Mark Tillotson]

These kind of potentiometer are use in a lot of mixer console.... but these pot are good for HI-FI audio ???

Somebody tried it ?

Purely by logic they must be good - if they were bad, all your studio-recorded music would already be damaged by them!


Anyway potentiometers are resistor-dividers which inherently tend to cancel out non-linearity - the benefit of a ratiometric topology. Of course not all uses of pots are as a potentiometer, sometimes they are wired as variable resistors and then the quality matters more (and any tendancy to crackling is intolerable).

 

[Handel]

I just asked from Curtiss-Wright and they told me that P&G RF15 is obsolete and there is no alternatives or spares for repairs

Need to repair my own. It can be opened.

 

[tiefbassuebertr]

A friend of me want to replace a P&G RF15 by an ELMA 04 with 24 positions (1 Wafer 1 x 24 Shorting 15°) - go to
https://www.elma.com/-/media/products/products-files/04_datasheet_e.pdf
In this case I note a lot of versions with different resistor types - go to
https://www.don-audio.com/Classi-Audio-Elma-12-to-24-Stepped-Attenuator-Series-Version
https://www.don-audio.com/Elma-A47-Jumbo-High-End-Switch-Assembled-Audio-Note-Vishay-Naked
https://www.don-audio.com/Elma-High-End-Audio-Rotary-switch-A47-10k-2-Wafers_1
Which kind of resistor should I prefer ?
Thank you very much for an advice.

 

[tiefbassuebertr]

No information ?
In the attachment various images of this P&G series - first image is those single channel potentiometer which is to be replaced by an ELMA "04"
Which resistor version for ELMA's 04 should I prefer ?