[dukecv]

     So a while back I got a tube amp kit off tubedepot.com, (model 16ls diy kit) and while I enjoy it a lot, the volume pot is very unbalanced at low volumes and it's like I can barely turn it up and it's loud as hell or if I turn it down it unbalanced and very touchy. It is a 100k pot currently. Would I benefit from a 250k alps pot off parts express or a 100k one of the same model? Just a little lost in this.

Thanks for any help.

[Folsom]

Value is a little hard to declare because I don't know the input impedance. The amount of gain may play a much larger factor with climbing volume. Anyways, these guys make pots seem rather pathetic


http://m.ebay.com/itm/DACT-Type-21-Stepped-Attenuator-Potentiometer-250K-D-shape-shaft-for-Tube-Amp-/191955510974?nav=SEARCH

[I.Greyhound Fan]

I am not sure what your budget is but I built a DIY Pass B1 preamp and bought a Motorized TKD and Blue Alps from here, shipping is fast and cheap-

http://www.hificollective.co.uk/components/potentiometers.html

The Blue Alps is warm and smooth sounding while the TKD is more revealing and detailed but brighter.  It is also built better.

I would take a look at the Khozmo attenuaters and the Elma-

http://www.hificollective.co.uk/components/stepped_attenuators.html

[FullRangeMan]

I had ordered the Khozmo 100K log some time ago, reliable seller and nice products, see photos at post 178:
http://www.audiocircle.com/index.php?topic=129713.160
Site:
http://www.khozmo.com/products_dale_shunt.html

[dukecv]

Well as for budget, the amp kit was  $199, so I was thinking of something not crazy expensive. Those kozmo attenuators are definitely far out there for this cheap tube amp. That's kind of the reason I was after just a simple pot vs a stepped attenuator. I'm also just not a fan of the stepping, unless it was something like 40-50 steps. But for the price of the one you linked to Folsom, it wouldn't hurt to check it out. Another question is how do I know whether I need a 100k or a 250k? It's currently a 100k

How could I figure out the input impedance Folsom? Would any pictures help? The one currently has 6 pins out the bottom, mounted directly to the pcb.

Thanks again guys.

[borism]

Another inexpensive option is the Valab 23 step ladder style attenuator:

http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-250K-Log-Stereo/302184228193?

It is quite popular on the Bottlehead forum for the Crack headphone amplifier kit. I have bought one but have not built it into the kit yet. There are 100k and 250K versions.

[I.Greyhound Fan]

Just buy a Blue Velvet Alps pot.  They work well, sound good and are cheap.  Partsconnexion sells them.

http://www.partsconnexion.com/product7386.html

If you want to go cheap to play around with different values, take a look at alpha pots.

[dukecv]

Simple and straight to the point. Sweet. Thanks greyhound. Was looking at that exact one but didn't know whether to get 100k or 250k.

[dukecv]

Input impedance is 100k. Does this tell me the k-ohm needed?

[I.Greyhound Fan]

Sorry I cant help you with the impedance question but the guys over on the DIY Audio forum are helpful.  I am currently building a Pass Bride of Son of Zen preamp  to replace the Pass B1 I built for and with my son and they have been helpful.

http://www.diyaudio.com/forums/tubes-valves/121806-value-potentiometer.html

[I.Greyhound Fan]

PM sent

[Folsom]

Input impedance is 100k. Does this tell me the k-ohm needed?

In that case I'd use a 10k. But your gain will still be high.

[I.Greyhound Fan]

I just wonder if the volume pot is linear and not logarithmic.  It also sounds like there is something wrong with it.

https://www.google.com/search?q=linear+vs+logarithmic+pots&espv=2&biw=1242&bih=602&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiiq8HxrKXRAhVJzoMKHapBAK8QsAQIeg

[FullRangeMan]

The usual Khozmo pots are 48 steps, there is various R values>
Resistance: 600R, 1K, 2K, 5K, 10K, 20K, 50K, 100K, 250 kohm or custom values.
SHUNT type: Only two resistors in signal path
Switching type: MBB (Make Befor Break)
Number of steps: 48
Attenuation range: -60 dB ... 0 dB

[srb]

Well as for budget, the amp kit was  $199, so I was thinking of something not crazy expensive. Those kozmo attenuators are definitely far out there for this cheap tube amp.

[FullRangeMan]

Well in view these budget restrictions I suffest a CD player with volume pot as the source, so it does not need a new pot for the amp.

[dukecv]

Thanks a bunch guys. I really wonder why they'd stick a linear pot on there in the first place, if that's the case.  I have an email out to S-5 Electronics asking them if they know whether it's linear or audio (log) taper. The Kosmo pot looks like a nice choice, but there is no way I could justify it. Just the situation I'm in. I'll keep you posted.

Thanks again
Cole

[dukecv]

Alright so here it is straight from S-5 Electronics:

Cole,
   It is linear, it is a standard stereo pot layout.
If you plan on moving the pot away from the pcb - use shielded wires or twist them to reduce the possibility of picking up oscillation or noise.

Larry
S-5 Electronics

Might be a dumb question but, what is a "standard" stereo pot layout? Is this basically what those alps pots would be? Never know if I don't ask.

[I.Greyhound Fan]

I think that you will be better off with a 100K Blue Alps pot.  Let us know how it sounds.

[Folsom]

Don't be fooled by the eBay DACT prices. They're so much better than Alps it's mysterious why Alps are used besides when one wants a motor.