Another idea for volume control on the FP III+

Jim R. · 29120

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4krow

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Reply #15 on: July 05, 2012, 10:34:13 AM
To try all this stuff out for 'comfort', a Quckie kit has been ordered with the optional upgrade. Along with that thinking, I believe that I will try the cheaper ($30) volume control first. If this all works as I think it should, who knows what will happen next? (Not even my entire team of psychiatrists are willing to bet on that one)



Offline Grainger49

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Reply #16 on: July 05, 2012, 10:39:28 AM
Greg,

Just for yucks try the 100k Alps Stereo Volume control from Radio Shack first.  It costs over $3 now, damn near $4, it used to be $2. 

http://www.radioshack.com/product/index.jsp?productId=2062359

Many say that the low level tracking is off but I have used them for over 20 years with no problems.

I mean, if you are going to do a survey of this stuff, start at the bottom.



Offline Laudanum

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Reply #17 on: July 05, 2012, 11:55:11 PM
I still have one of those Alps pots on a half kit I built.  I bought a Blue Velvet to replace it but never got around to it.   Mine actually tracks fairly well but listening level on that amp is usually 11 O'clock or higher.   Actually I think those little S5 kits had/have a version of the same control.   I have one of the older/original S5 kits with the 11BM8 tubes that sounds better than any amp under 100 bucks has any right to.  A pair of full rangers with Fostex drivers crank on that little amp.  That little kit with it's cheap transformers, run of the mill PCB and cheap passives along with an old Scott 299B is what started me back with tube audio gear a dozen years ago.  Those cheap wirewound Alps pots sound fine to my ears but with 2 disclaimers.  First, I havent compared them to anything else in those amps.  And second, MY EARS being the operative words.  They probably arent quite tin but they are closer to tin than gold   ;D

Desmond G.


4krow

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Reply #18 on: July 06, 2012, 02:35:50 AM
Well, I do have an ALPS that has been orphaned by the PEC.



Offline Tickwomp

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Reply #19 on: July 06, 2012, 04:57:43 AM
How about a remote control?


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4krow

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Reply #20 on: July 06, 2012, 04:59:14 AM
Hey, now, I don't need that...I'm married.



Offline tuffy_puppy

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Reply #21 on: July 06, 2012, 07:33:39 AM
hi again,  here is a small demonstration of my ongoing ignorance.  my components are placed on a big ol' sturdy coffee table at arms length directly in front of me.  an efp 3, a sex 2.1, a decware cd 200i and an old carver fm tuner.  my speakers are audio nirvana 12 inch and are flanking the components at around 70 inches from my ears.  this idea was stolen from pierre at mapleshade audio.  i have been set up this way for over six months now and will most likely NEVER return to the "rule of thirds"..........no remote control,  no tedious walks back and forth to change sources, or discs, or volume adjustments.  walking back and forth to a set of controls is not my idea of a good listening experience.  no room treatments seem to be required.  other sorts of things that will not come to mind right now.............i'm hoping that some out there will have comments that i may learn from.  are any of you experienced with this method and know stuff i am missing??  don



Offline Jim R.

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Reply #22 on: July 06, 2012, 11:03:56 AM
Hey Don,

If it works for you, that's all that really matters, right?  I have to admit to being a past skeptic, now turned believer in Pierre's often whacky methods.  Some of it is really, really hard to get your head (and eyes) around, but he and Ron are eccentric geniuses with impeccable engineering credentials.

I was completely skeptical of their power strip but got to demo one in my place a few weekks ago (one of the "Stratum AC conditioners -- power strip mounteed on a maple block) and was stunned, literally, at the difference.  Unfortunately I can't use the speaker wires or interconnects as my cat loves to chew on bright shiny things and plastic films, and it doesn't take much to get that insulation off -- which is bad for the electrical gear, and worse for the cat.

Anyway, back to the subject at hand, I see I had misinterpreted how the FP III+ volume control hooks up, and not that I've got it figured out, I've gone ahead and ordered a 25k 48-step khozmo ladder attenuator and will play with the padding resistor until I find the right balance of adjustability and overall gain.  I'm also going to put the resistors between the selector and the pot to keep things simple and reduce the possibility of noise pickup.  I don't really need each input to be level maatched as I will have somewhat more than 11 steps to work with.  I'm also using a single stereo control and will place it on the opposite side from the power switch.

Problem solved, case closed. :-)

-- Jim
 

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline earwaxxer

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Reply #23 on: July 06, 2012, 01:15:02 PM
hi again,  here is a small demonstration of my ongoing ignorance.  my components are placed on a big ol' sturdy coffee table at arms length directly in front of me.  an efp 3, a sex 2.1, a decware cd 200i and an old carver fm tuner.  my speakers are audio nirvana 12 inch and are flanking the components at around 70 inches from my ears.  this idea was stolen from pierre at mapleshade audio.  i have been set up this way for over six months now and will most likely NEVER return to the "rule of thirds"..........no remote control,  no tedious walks back and forth to change sources, or discs, or volume adjustments.  walking back and forth to a set of controls is not my idea of a good listening experience.  no room treatments seem to be required.  other sorts of things that will not come to mind right now.............i'm hoping that some out there will have comments that i may learn from.  are any of you experienced with this method and know stuff i am missing??  don

don - I kind of like that idea! I worry about people (like me) and their coffee in close proximity to my gear! I guess in a dedicated listening room - for sure.

Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.


Offline tuffy_puppy

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Reply #24 on: July 06, 2012, 01:37:05 PM
to jim's topic:  recently asked  a fellow bottlehead to install a goldpoint mini-v unit into my sex 2.1.  that improved it so much i am almost speechless.  along with some other upgrades this li'l guy is better performing that my wife tells me i deserve!  grateful!....so now he is receiving my efp 3 in order to do similar upgrades.  and then i happen upon mention of khozmo.  look it up and behold!  machinery heaven!  and then i read that quite knowledgeable people are turning to khozmo instead other stuff.  i am just about to make a purchase.  any ideas?  don pettit



4krow

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Reply #25 on: July 06, 2012, 03:05:23 PM
Don, I just looked at the Khozmo, and again, I couldn't be more impressed with the build quality. Simply amazing, but about the sound? I can't answer that. I can tell you that the cheap Chinese stepped attenuator that I tried out on my amp was taken out and replaced with a PEC control.I really like it, BUT it doesn't have any more control that the ALPS I started with(of course, being the same value and taper I didn't expect it to). Anyway, the Khozmo has 41 steps. That is quite a bit of control if the taper is right, and the pad resistors are chosen well. We can try using that one in your EFP III if you want, and like I said the last time, I will buy it if you aren't amazed by it.



Offline Jim R.

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Reply #26 on: July 06, 2012, 03:26:43 PM
Greg and Don,

I got the ladder type -- meaning the one with 48 steps and non-SMD resistors.  That said, I have no idea if it will fit in a stock foreplay III, but as I'm making my own top plate, I will be able to adjust the positions of some things a bit, though the basic layout and spacing will be retained.  Mainly I'm getting the IEC inlet off the top and will put one on the rear or use a PowerCon.  If there's room I'll probably also put the power switch somewhere in that rear corner where the iec inlet was.

HTH,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline John Roman

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Reply #27 on: July 07, 2012, 07:36:59 AM
Informative thread, thanks. I'm curious though, I recently removed a pair of Goldpoint Mini-V's (with Nichrome thin film resistors) because I heard a distinct change in tone. I'm not sure exactly how to describe it except to say the tone became somewhat veiled, less musical. I disliked it so much I reinstalled the sweetest whispers attenuators. I haven't had a chance to listen since as my speakers are in a state of change. The Khozmo attenuator looks as though it uses similar surface mount resistors, Resistors: 1% 100ppm , 1/10W, low noise, non-inductive. The surface mounted resistors used on the standard Goldpoint Mini-Vs are 0.1% Nichrome THIN film with a thermal noise specification (TCR) of 25 PPM or 50 PPM. Thin film as opposed to metal film. A small difference perhaps but "we" DIY to chase the grail in a more value conscience way. Frustrating though. But then again I've learned more about resistors this morning, now if I can only remember it all :)
Best regards,
John


Regards,
John
Extended Foreplay 3 / 300B Paramount's / BassZilla open baffle/ Music Streamer 2 / Lenovo Y560-Win7-JRMC & JPlay


Offline tuffy_puppy

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Reply #28 on: July 07, 2012, 08:52:41 AM
hi john,  to my ears, in my sex 2.1,  i heard a vast improvement when the mini-v was installed to replace the stock unit.  greg seems to have heard the same thing. so far so good.........now, turning to my efp 3 i am thinking why not the same improvement here?  but i do recognize the ballgame may well be entirely different.  since i am not a diy person and the preamp is in the hands of greg i have this decision to make.  drat,  i don't really know what to do.  $180 or khozmo or $150 for goldpoint or $4 at rat shack? myohmy!!!!!!!!!!! don



Offline Doc B.

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Reply #29 on: July 07, 2012, 09:11:47 AM
You are replacing completely different attenuators in S.E.X. and FPIII. S.E.X. has an inexpensive Alpha pot and FPIII uses a stepped attenuator with thru hole metal film resistors. IMO the Mini V sounds quite a bit better than the Alpha, but not quite as good as an attenuator made with thru hole resistors. This is why I recommend buying the Goldpoint Mini V Custom that uses thru hole resistors for the S.E.X. amp. Arn is a great guy to deal with.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.