Stepped attenuator recommendation...

[69CamaroSS396]

for use with Mikael Abdellah's SE KT88. I've searched and searched and maybe that's part of my problem. There are all kinds of conflicting things to read if you do enough looking.

I'm a bit leery of those $20 deals on ebay. Conflicting reports on those, as well.

I want something to be of comparable quality to the rest of the build. It's going to be a stereo, one chassis version. I'm using EH KT88s. Plan is to buy a couple of other brands for experimentation. Maybe something vintage. Using a Russian 6N1P, with several 6922 and 6DJ8 variants to play with.

Mains xformer is the universal Angela. That would have been different had I looked more closely at the size factor before ordering. It's monstrous. I still may change that. I have a mint, vintage Chicago Transformer of the correct specs except it has no provision for 5V. It's literally half the size of the Angela. I have a filament xformer I could mount under the chassis and use for the RCA 5U4G in the PSU.

Nice sockets from Angela. OPTs are Transcendar. Russian PIO, Black Gate, Solen, and BHC caps. Resistors will most likely be the Roedersteins that Michael Percy has. Hook up wire from Percy.

Percy also has some reasonable prices on some of his attenuators. Tempting.

I'm not a tightwad, and I'm willing to buy what I need. But I don't want something that is unnecessary overkill. I'm not trying to "impress" anyone by saying I have this brand or that brand. This is strictly a "what is best for this particular build" thing.

Thanks and regards, Greg

[Eli Duttman]

Greg.

PEC hot molded Carbon controls cost less than good stepped attenuators, while sounding better too boot. An added benefit that comes with the PEC controls is MILSPEC toughness, for long service lives.

DigiKey is the place to buy PEC controls.

[69CamaroSS396]

Eli,

Thanks for that idea. That is one option I hadn't heard until now. The more I learn, the more it amazes me what I don't know.

Thanks again, Greg

[69CamaroSS396]

After looking for the PECs at Digi-Key, the ones I found are all linear taper. No audio tapers, unless I missed something.

[69CamaroSS396]

Ignore that previous post. I found them under log taper. Seems there are some nice ones to choose from.

[Eli Duttman]

You missed something. This is the DigiKey catalog page of interest.

The KA (single) and KKA (ganged) parts series are what you are interested in.

[69CamaroSS396]

Thanks again, Eli. I submitted my order for the KKA 100K version.

Any thoughts on why the PEC pots are rarely mentioned in discussions, or have I just missed it. It's not like I'm a veteran at building, but I have been lurking for years before the '"plunge". It seems like such a great option to be able to pick this up from Digi-Key.

Ha! Ha! I should have made this post before spending the last week wearing out Google.

[kmaier]

Any idea on how tight the tracking between sections is? PEC does not list any spec, only tolerance of 10% or 20%, presumably for the resistance value. They should give excellent service life. TKD also make some "reasonably" priced units and offer a balance control.

Regards, KM

[Ty_Bower]

Originally posted by 69CamaroSS396
It seems like such a great option to be able to pick this up from Digi-Key.

I always thought it was a great option to be able to pick up the 100K Alps pot from the local Radio Shack for only $3.50. Unless I'm missing something, the PEC pot is $32.42? Is it really worth the 10x price premium?

Originally posted by kmaier
TKD also make some "reasonably" priced units and offer a balance control.

How reasonable is it?

[Eli Duttman]

I always thought it was a great option to be able to pick up the 100K Alps pot from the local Radio Shack for only $3.50. Unless I'm missing something, the PEC pot is $32.42? Is it really worth the 10x price premium?

Alps or Alpha (Taiwan)? Mouser carries Alpha for less than R/S charges.

As to the worth, the PEC stuff is made BETTER. The wiper is a block of Carbon, not a piece of metal that causes early wear. MILSPEC certification does not happen by accident. By all accounts, PEC sounds better. Yet, another consideration is the cost of Canadian, as opposed to Taiwanese, labor.

BTW, Alpha (Taiwan) Carbon controls are pretty good. When funds are limited, A/T is an excellent choice.