CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => DIY => Topic started by: Anaxilus. on February 10, 2013, 04:20:47 AM
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Original shouts on pots (from bottom to top):
n3rdling (http://www.changstar.com/index.php?action=profile;u=24):a lot of people have had noise issues with their khozmo pots, i think Today at 03:30:00 PM
dBel84 (http://www.changstar.com/index.php?action=profile;u=41):omega / anax - what ever happened to khozmo - those early pots they had looked pretty substantial. Today at 02:39:11 PM
shipsupt (http://www.changstar.com/index.php?action=profile;u=31):cool, if you grab it again send it over... I have a DACT and a Khozmo standing by for a few builds, but I'm not sure I want to put the Khozmo in anything, i hear to many issues with them Today at 11:00:54 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):the P&G looks pretty ordinary :p but it's nice it doesn't take up much space Today at 11:00:22 AM
prtuc2 (http://www.changstar.com/index.php?action=profile;u=488):guess learn something new again before Chinese New Year Today at 11:00:00 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):ship, I'm gonna have to dig out that info, I have a pic somewhere and the model number. It looks like a chromed RK50 w/ jewel like build from Rolex. Today at 10:58:47 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):especially if it's not on max, you are still attenuating and likely introducing miller capacitance. Today at 10:57:30 AM
shipsupt (http://www.changstar.com/index.php?action=profile;u=31):omega, that looks like a pretty slick set up Today at 10:57:04 AM
shipsupt (http://www.changstar.com/index.php?action=profile;u=31):its not just about changing the volume or channel imabalance, its about transparancy, so id say yes it still makes a difference even if you dont touch the pot after you get it set Today at 10:55:45 AM
prtuc2 (http://www.changstar.com/index.php?action=profile;u=488):does the attentuator make much of a difference if you don't touch your volume pot after first use? Today at 10:51:29 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):these are the things i plan to use in my preamp [link] (http://bentaudio.com/rempics/safboth.jpg). from listening tests they're more transparent than any resistor switch or carbon pot. but overkill for headphone amps since it has so much other stuff it needs to work Today at 10:51:11 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):it's the home page, one sec Today at 10:45:38 AM
shipsupt (http://www.changstar.com/index.php?action=profile;u=31):why am I only getting the splash page for spectrum control? Do you guys have a link right to the attentuator you were looking at? Today at 10:45:01 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):I'll do that, see what happens. Today at 10:42:13 AM
shipsupt (http://www.changstar.com/index.php?action=profile;u=31):I'm less interested in attentuators now that I have the M51, it handles volume duty now. Today at 10:40:08 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):for $250 if that is 4-ch and has pcb mount you should definitely get in contact with justin. he has mentioned more than one occasion looking for a DACT replacement. since they are truly built like shit Today at 10:39:43 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):'comparatively'. It's a less refined build for a brass brick is all. It's solid. We're comparing ToTLs here, not blue velvets hehe. Today at 10:39:31 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):cool. someone else will have to take the initiative, i will be cannibalizing this P&G for my next amp (it's good enough for me) and using AVCs in my preamp. the RK50 is like a brass kilo brick, not sure how it's built poorly Today at 10:38:11 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):I tried to get Jason to get some for the Statement but he's doing more crazy Schiit I can't talk about. Today at 10:37:51 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):I know Craig measured the samples he had and the measurements blew him away comparatively. He's had tons more experience w/ the RK50 and PnG than myself. The only reason he doesn't use them is he doesn't move enough volume. Today at 10:32:51 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):The Spectrum pot makes the RK50 look like a Chinese clone in build quality. Today at 10:28:53 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):Yup, the Levi had the PnG and the RK50 was in the BHSe I believe. Of course it's not apples to apples but you get a sense for how the pot behaves and sounds through the range, I'm sure you get my drift. I think they would go from around $250 per give or take depending, that's for a very high minimum batch order. Today at 10:27:59 AM
firev1 (http://www.changstar.com/index.php?action=profile;u=263):hmmm, nice stuff there Today at 10:19:50 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):how much? and have you compared them to the two i mentioned Today at 10:15:15 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):Let me know if you guys ever arrange a GB over on HC for these Today at 10:09:16 AM
Analixus (http://www.changstar.com/index.php?action=profile;u=4):Nope, I know another that's better than both. I told KG about hoping it would eventually turn into a Justin GB or something, didn't seem to trickle over. Today at 10:00:08 AM
omegakitty (http://www.changstar.com/index.php?action=profile;u=68):listening to an amp with a P&G RF15. this might be the only pot besides RK50 that has zero channel imbalance right after max attenuationToday at 08:37:05 AM
Spectrum Rotary Pot w/ custom spec'd taper:
http://www.spectrumcontrol.com/ (http://www.spectrumcontrol.com/)
(http://i.imgur.com/2LryBqpl.jpg)
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I initially opted for an RK27 for my Dynalo build but as the build progressed I found an early revision Joshua Tree for 60$ that needed repairs. There was a subtle change in detail and maybe it sounded a tiny bit less lush. Most likely due to the impedance change "seen" by the DAC output. The resistors used in the relay board were regular 1%'ers.
There's no doubt that setting up a relay board is a bit of a hassle as it takes up a lot of enclosure space (2 pcbs + transformer), but in my opinion it's hard to get shorter signal path with regular potentiometers. There's also the issue of noise when the relays are clacking but I usually can't hear it through the music. I once saw a surround system preamp with five or more of these boards... It must sound like a machine gun range. There is, however one thing that I consider a big plus for relay based attenuators- they purr when you have DC coming from DAC outputs. When you have zero DC input you most likely won't hear a thing when adjusting volume (save for the steps when all the relays switch), but when I had 0.5VDC coming from my DAC due to misadjusted output buffers there was a distinct motorcycle sound/purr. Good for me that I had DC servo on my amp!
I also highly regard quality digital attenuation as found on Buffalo and other DACs, very convenient in my opinion. If I'd knew I settled for such a DAC I'd surely build my future headphone amps without any attenuators to keep shorter signal path. Heck, my Dynalo has preamp output that can be switched from passive to active! I might build a simple tube amp without an attenuator just for the kicks!
I also know that there used to be this Lightspeed attenuator project at DIYA. I remain skeptical about it because optical resistors do have noise characteristics among other things that are not superior to quality regular resistors. Also the guy who proposed the Lightspeed attenuator said that there is a diode effect in potentiometers where wiper touches the conductive material. I also have a hard time buying this.
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Mike, are those offered in 4 chan versions?
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Mike, are those offered in 4 chan versions?
I was poking around the web site after Mike posted it... seems you can create a custom pot. I wonder how over the top you could go with these guys?
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7.1 ch home theater preamp with balanced connections over the top?
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Damn! I came here to recommend the BBC Documentary "The Evil Weed"
From that pic, still not seeing how it's built better than the RK50 :P The RK50 is completely potted, and I'm seeing a set of screws on the Spec to hold it together. One thing that would get a lot more people interested in Spec is if they offer higher than 10k/20k input Z. I think P&G only offer 10k
If you must have something "now" the US dealer for P&G minimum purchase quantity is 2. I've played with the RK50 and RF15, and I would never pay RK50 prices again (even the "deal" at $580 is not so great in comparison). The P&G is similar to the RK50 in that it continues max attenuation a bit past 7 o'clock so there isn't imbalance even with the most sensitive headphones. The other thing is longevity is a well known with P&G; there is British professional gear from 40 or 50 years ago using their faders that still work.
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I think for general decent quality , the TKD pots are reliable. They do have some imbalance right at max attenuation but as soon as you get it into listening range, it works a charm. I think worth the price difference from the ubiquitous RK27. I honestly wish the alpha pots that Birgir had made were generally available, I preferred them to the TKD and the one I had had no imbalance at max attenuation. @ $25 a pot, they were very hard to beat.
I have not played with relay based or digital attenuators at all , I have a few that I had been meaning to play with but other things always seem to come up.
..dB
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Mike, are those offered in 4 chan versions?
I was poking around the web site after Mike posted it... seems you can create a custom pot. I wonder how over the top you could go with these guys?
Check out their clients. They'll build anything you want as long as you buy enough of them.
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Throw out the pineapple and rock LDR? :-Z https://docs.google.com/file/d/0B0N-dmOQiKmAYTZmMDdjNDUtZTkyOS00YjU2LTk1ZDEtZjZiYjg1OTNjMzdm/edit?pli=1&hl=en (https://docs.google.com/file/d/0B0N-dmOQiKmAYTZmMDdjNDUtZTkyOS00YjU2LTk1ZDEtZjZiYjg1OTNjMzdm/edit?pli=1&hl=en)
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From that pic, still not seeing how it's built better than the RK50 :P The RK50 is completely potted, and I'm seeing a set of screws on the Spec to hold it together. One thing that would get a lot more people interested in Spec is if they offer higher than 10k/20k input Z. I think P&G only offer 10k
The picture doesn't do it justice, I what's on the inside would matter more. ;) Like I said, it's a custom spec'd sample unit and Spectrum wouldn't let us keep it or buy it off them.
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I think for general decent quality , the TKD pots are reliable. They do have some imbalance right at max attenuation but as soon as you get it into listening range, it works a charm. I think worth the price difference from the ubiquitous RK27. I honestly wish the alpha pots that Birgir had made were generally available, I preferred them to the TKD and the one I had had no imbalance at max attenuation. @ $25 a pot, they were very hard to beat.
I have not played with relay based or digital attenuators at all , I have a few that I had been meaning to play with but other things always seem to come up.
..dB
I agree the TKDs are pretty decent when they were around $50 (though a few people on H-C have said they have gotten ones with noisy wipers, never had an issue with mine). Now PCX and Michael Percy sell them for $100. And I believe the quads are around $250 from Germany.
I have some imbalance in my quad alpha at the start. They are a tremendous value for $25.
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I think for general decent quality , the TKD pots are reliable. They do have some imbalance right at max attenuation but as soon as you get it into listening range, it works a charm. I think worth the price difference from the ubiquitous RK27. I honestly wish the alpha pots that Birgir had made were generally available, I preferred them to the TKD and the one I had had no imbalance at max attenuation. @ $25 a pot, they were very hard to beat.
I have not played with relay based or digital attenuators at all , I have a few that I had been meaning to play with but other things always seem to come up.
..dB
I agree the TKDs are pretty decent when they were around $50 (though a few people on H-C have said they have gotten ones with noisy wipers, never had an issue with mine). Now PCX and Michael Percy sell them for $100. And I believe the quads are around $250 from Germany.
I have some imbalance in my quad alpha at the start. They are a tremendous value for $25.
i've soldered numerous TKD pots without noise issues. i do wire up with temporary roach clips before soldering since PCX won't accept a noisy TKD that's been soldered. i can only infer that PCX thinks it's the end user using too high soldering temps. i'm not sure if this an issue of too high soldering temp or the manufacturer though. the knob and pot shaft need to be tied to chassis as a general rule. i assume they must use some conductive grease between the pot shaft and threaded mounting barrel.
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I think for general decent quality , the TKD pots are reliable. They do have some imbalance right at max attenuation but as soon as you get it into listening range, it works a charm. I think worth the price difference from the ubiquitous RK27. I honestly wish the alpha pots that Birgir had made were generally available, I preferred them to the TKD and the one I had had no imbalance at max attenuation. @ $25 a pot, they were very hard to beat.
I have not played with relay based or digital attenuators at all , I have a few that I had been meaning to play with but other things always seem to come up.
..dB
I agree the TKDs are pretty decent when they were around $50 (though a few people on H-C have said they have gotten ones with noisy wipers, never had an issue with mine). Now PCX and Michael Percy sell them for $100. And I believe the quads are around $250 from Germany.
I have some imbalance in my quad alpha at the start. They are a tremendous value for $25.
i've soldered numerous TKD pots without noise issues. i do wire up with temporary roach clips before soldering since PCX won't accept a noisy TKD that's been soldered. i can only infer that PCX thinks it's the end user using too high soldering temps. i'm not sure if this an issue of too high soldering temp or the manufacturer though. the knob and pot shaft need to be tied to chassis as a general rule. i assume they must use some conductive grease between the pot shaft and threaded mounting barrel.
One instance was solved by cleaning the wiper with some conductive goop, so probably something internal.
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I think for general decent quality , the TKD pots are reliable. They do have some imbalance right at max attenuation but as soon as you get it into listening range, it works a charm. I think worth the price difference from the ubiquitous RK27. I honestly wish the alpha pots that Birgir had made were generally available, I preferred them to the TKD and the one I had had no imbalance at max attenuation. @ $25 a pot, they were very hard to beat.
I have not played with relay based or digital attenuators at all , I have a few that I had been meaning to play with but other things always seem to come up.
..dB
I agree the TKDs are pretty decent when they were around $50 (though a few people on H-C have said they have gotten ones with noisy wipers, never had an issue with mine). Now PCX and Michael Percy sell them for $100. And I believe the quads are around $250 from Germany.
I have some imbalance in my quad alpha at the start. They are a tremendous value for $25.
i've soldered numerous TKD pots without noise issues. i do wire up with temporary roach clips before soldering since PCX won't accept a noisy TKD that's been soldered. i can only infer that PCX thinks it's the end user using too high soldering temps. i'm not sure if this an issue of too high soldering temp or the manufacturer though. the knob and pot shaft need to be tied to chassis as a general rule. i assume they must use some conductive grease between the pot shaft and threaded mounting barrel.
One instance was solved by cleaning the wiper with some conductive goop, so probably something internal.
makes me want to call up PCX or Michael Percy to find out the scoop. maybe Don can chime in with some insider knowledge considering Alex uses TKDs.
i soldered in yet another TKD pot tonight after roach clip testing and dead silent.
i like the PEC carbon pots as well, but 2 out of the 5 stereo log pots i bought are noisy. the noisy ones were not a problem with a preamp/amp driving speakers from a distance. i complained once to Digikey and they said it wasn't worth they're time or money to have me send it back, so they sent me a new one which turned out to be noisy too. i've been meaning to rip then apart and clean with ProGold, but they're well sealed with bent steel locking tabs and without easy access screws.
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Just got this HUGE Shallco open frame to build out. I put a Khozmo and DACT next to it to show off how fracking big it is.
(http://img.photobucket.com/albums/v152/shipsupt/shalco_zps6a5e3b54.jpg)
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that's freakin' huge. i'm still leary about the Khozmo. has their QC improved recently?
i'm building a balanced amp and am exploring other options for a quality SA/pot that doesn't take up too much space. i do really like the Goldpoints and think they're very reasonable. i was quoted $445 for a balanced P&G with a 6wk lead-out time from the UK. other options include a custom 4 deck Grayhill 53 series for a series configuration, or even 2 of these for separate L/R control and could go L-pad. these are cute: http://www.acoustic-dimension.com/tkd/Tokyo-Ko-on-Denpa-TKD-36R-stepped-attenuator-kit.htm (http://www.acoustic-dimension.com/tkd/Tokyo-Ko-on-Denpa-TKD-36R-stepped-attenuator-kit.htm).
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And it takes some torque to turn! I have a feeling the build is going to be tedious as heck.
I'll let you know on the Khozmo's. I have two that I accumulated. I'll use one of them or the DACT there in the KGSShv I'm boxing up right now.
I've become less interested in pots since I got the M51, I love it's digital attenuation. I pretty much set the amp I'm listening to and use the M51.
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Wow, that thing is huge.
My last build had relays. I think I'm sticking with that route, even if it means extra power transformers/circuitry. I like the steps. I've not had checked the TOTL pots before. I can't really say I would be able to tell a difference without an ohmmeter.
How many steps in that thing?
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Wow, that thing is huge.
My last build had relays. I think I'm sticking with that route, even if it means extra power transformers/circuitry. I like the steps. I've not had checked the TOTL pots before. I can't really say I would be able to tell a difference without an ohmmeter.
How many steps in that thing?
nice to see you here holland ahoy.
any relay based attenuators you recommend? this one looks small but without the bells and whistles of a delta1: http://www.8thnote.eu/attenuator_details.html (http://www.8thnote.eu/attenuator_details.html) .
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Thanks fishski! Good "seeing" some familiar names around!
I used DIYGene's V-03 (along with his chassis) for my EHHA build. It has 100 steps @ 1dB. That was my last build about 2 years ago. I am going to finally build my Dynahi (old djgardner boards), and will look into that 8th note one if my transistors are real. I was just wondering why there are no SMT stuff. I was going to use a Joshua Tree.