attenuators

[John Roman]

I installed some 20K Goldpoint attenuators along with a 4 pole 3 position selector switch from Goldpoint in my EFP3. Now I have no volume control. I can't attenuate either channel no matter what output I use. When I switch to that output I get max volume. I've checked the attenuators and selector out of the circuit and they appear to be working normally.
John

[earwaxxer]

yep - sounds like the attenuator is out of the circuit. That happend to me once. Fortunately the song didnt start out real loud! The song started with a dog barking. I was really faked out. It sounded so real!. Those are the kind of story we will tell our grand kids or great grand kids! Naah.. probably not!

[Laudanum]

Not meaning to Hi-jack here but have a question related to attenuators.  My memory was that these attenuators (sweetest whispers, right?)  were really well received when Bottlehead released them way back when.   Lots of chatter for how good they sounded, outright let alone bang for the buck.   Im sure there are many who feel there are better sounding stepped attens. for more money, there always are.  But my question is,  and this is highly subjective,  how much is gained, sonically, by upgrading the attenuators to something "affordable", like Goldpoints for example?   Are we talking about the barely audible IF one is golden eared, maybe 2 or 3% improvement?  Are we talking about clearly audible changes that definitely change the sonics but whether it is "better" or not is a personal opinion?  Or are we talking a definite improvement that most would agree upon?    I have read that some (many)  did not find the smd resistor Goldpoints to be better at all, they felt they were downgrades.  That makes me wonder how much improvement, if any, can really be expected from something like Goldpoints with leaded resistors.   

My selector switch has no stops,  it operates fine in the 3 positions, but it rotates beyond those 3 active positions is both directions.   There is too much wiring involved to bother with just replacing the switch for missing stops.   But I would replace it with a different Selector if I were to also "upgrade" the attenuators.   I have no real hankering to do so because of my memory of how well the stock attenuators were received by the diy community back when.   And, I am very happy with the FPIII and the system.  Im not one to always be looking for improvements. As long as it sounds good (and is quiet, that's my biggest peeve really) Im content to just enjoy the music.   So,  I ask for subjective opinions on the above questions, probably more out of curiosity.

Basically,  I guess Im asking ... how good are the stock attenuators considered to be these days?

[Paul Birkeland]

Hello John,

It would help to know how you have these wired.  The Goldpoints have an input, output, and ground, if you could let us know where each of those terminals is connected, that should help.

-Paul

[earwaxxer]

High Desmond - I dont think you are going to find much of a 'review base' on attenuators. IMO, its not a BIG issue. There are plenty of really smart designers/engineers of current excellent sounding high value gear that still use the Japanese go-to pots, the Alps Blue Velvet (Burson, Schiit, Peachtree etc). The current agreement is that the stepped pot using discrete resistors for each step sound 'the best'. You could probably debate about what brand or type of resistor sounds better than another. Another rage is the opto-potentiomiter. - Probably worth buying a few different types and experimenting.

[corndog71]

I've used Sweetest Whispers, Radio Shack pots, PEC pots, and have heard in other equipment various forms of stepped attenuators.  They all make an audible difference.  My one problem with some of the cheaper stepped attenuators was that the switch would get noisy over time and required cleaning which can be a real pain.  I haven't heard Goldpoint or Dact attenuators but have read many mixed reviews of both.  I've also read about the optocouplers and while they seem promising they are quite a bit more expensive.

I prefer the mono PEC pots which are relatively cheap (~$11ea) and sound really good.

[John Roman]

Hey Desmond,
In the FWIW column having listened to both the SW and GP (with SMD) attenuators and selectors I believe the difference is subtle. The quality of the GP switches are better, but then they should be at $80 a pop.
I do think the SW set up competes very well sonically with the GP (with SMD resistors). In fact I think it exceeds the GP's. I made a judgement mistake in not getting the GP custom mini V pots but have chosen to live with it until the new Pre comes out.
HTH,
John

[John Roman]

Hello Paul,
Here is how the Goldpoint 20K pots are wired:
left channel: in to 17U,  ground (blk) to 16U and common on pole 3 of selector switch and out to common on pole 4 of selector switch.

right channel: in to 37U, ground (blk) to 40U and common on pole 2 of selector switch and out to common on pole 1 of selector switch

Thanks for helping,
John

[Paul Birkeland]

From what I can tell, that is correct.  What's coming to mind immediately is that if you removed all the series resistors at the input, you would end up with the volume control acting as a variable load instead of an attenuator, and this would present the symptoms you have.  If you'd like to remove all those resistors at the input, you can do this if you rewire the Goldpoints "as directed" on the PCB of the switch body. 

If I'm totally off here, feel free to post a close-up pic of one of the switches as-wired and we can take a peek. 

[John Roman]

hello Paul,
Here's some pix. LMK what you think.
John

[Laudanum]

Thanks for the input everyone.  And again John, sorry to Hi-jack your thread.

[howardnair]

from selector switch-red to in of vc -black to out of vc-from out of vc-- to terminals 40 and 16---ground  from vc to 37 and 17

[John Roman]

No worries D, how you doin?
J

[4krow]

Having done a similar swap recently with the GP parts, it seems that the GP  'C' at the selector switch should go to the INPUT of the GP volume control, and not the OUTPUT. This would give you a reversed volume control the way it is now. The rest of the connections I can't remember the order that they go in or to.

[Paul Birkeland]

Odd, this actually looks to be hooked up correctly, though as others have mentioned, you can go from the selector switch to "In" and then wire the output to the preamp circuit, but it should work as-wired. 

It would be good to verify that the attenuator is working, can you place a probe on "GND" and a probe on "OUT", then measure the resistance as you turn the knob (with the preamp unplugged of course), then report back.  I also didn't see it in your origninal post, but I'd assume that the preamp was working without the Goldpoints?