Volume control mod

LordCloud · « **on:** 3 Dec 2004, 09:03 pm »

Anyone know of a company that can "affordably" replace my volume control on my tubed linestage with a stepped attenuator? The closer to Utah the better. Thanks guys.

doug s. · « **Reply #1 on:** 3 Dec 2004, 09:44 pm »

Quote from: LordCloud

Anyone know of a company that can "affordably" replace my volume control on my tubed linestage with a stepped attenuator? The closer to Utah the better. Thanks guys.

not sure if they would actually do the install for ya, but they mite... after all, they *do* perform a lot of work themselves!
http://www.diycable.com/main/default.php?cPath=31_71_77

doug s.

JoshK · « **Reply #2 on:** 3 Dec 2004, 10:38 pm »

do you have the parts in question already, or do you need the modder to order it for you?

LordCloud · « **Reply #3 on:** 3 Dec 2004, 11:34 pm »

Quote from: JoshK

do you have the parts in question already, or do you need the modder to order it for you?

I would need the volume control ordered by the modder.

ohenry · « **Reply #4 on:** 4 Dec 2004, 01:28 am »

You may have heard of this before, but just in case:
I've read quite a few good things lately regarding volume controls that are shunted to ground. The signal passes through one high quality resistor instead of the potentiometer, therefore, it's simple to implement, sounds great and relatively inexpensive. The accounts I've read indicate that it's an excellent alternative and it's something I'm going to try. There are a few schematics on the web if you're interested. Just a thought. . .

JoshK · « **Reply #5 on:** 4 Dec 2004, 01:38 am »

Yeah and it is really easy to do yourself. Get the best resistor you can find, something like Riken Ohm, because you only need two.

Ulas · « **Reply #6 on:** 4 Dec 2004, 02:09 am »

LordCLoud, the pertinent questions are:
Is there enough room in your preamp to accommodate a stepped attenuator?
Is your preamp good enough to warrant the upgrade?
Are you willing to pay the price?

randytsuch · « **Reply #7 on:** 4 Dec 2004, 02:25 am »

But, this is tubed stuff, so it has lethal voltages, you would need to be carefull. If there are no bleeder resistors, the voltages are stored in the caps, so it is still dangerous even if turned off.

Randy

mgalusha · « **Reply #8 on:** 4 Dec 2004, 03:05 am »

Henri,

The DACT is probably the smallest of the stepped attenuators and will likely fit with the least problems. Unfortunately it's mighty expensive at $180 from DIYCable. As others have said, this is a very straightforward job but caution is in order, especially with tube gear. A volume pot in shunt mode can be very good but there is some variation in input impedance with volume. I've used them before with good result.

I'm willing to do the install if you like. Now, if I'd just known about this before I sent you the check for the Ray Brown XRCD.

PM me if you 're interested.

Mike

markC · « **Reply #9 on:** 4 Dec 2004, 03:26 pm »

I had great success with Goldpoint stepped ladders. Quite expensive, but worth it in my opinion. Check their website for dimensions and pricing.

nhtran · « **Reply #10 on:** 8 Dec 2004, 10:55 pm »

Quote from: markC

I had great success with Goldpoint stepped ladders. Quite expensive, but worth it in my opinion. Check their website for dimensions and pricing.

There is a guy on ebay selling attenuators similar to Goldpoint for much less. Do a search there for stereo stepped attenuator. Only problem is the seller is located in Hong Kong.....

LordCloud · « **Reply #11 on:** 9 Dec 2004, 06:46 pm »

How do I know what attenuator to buy, i have read that there are different "values"? for different applications, different ohms or something or the other? I am not inclined in these types of things, and I don't want to buy one only to have a compatibility problem. Thanks a lot for the responses guys.

nhtran · « **Reply #12 on:** 16 Dec 2004, 04:27 pm »

Quote from: LordCloud

How do I know what attenuator to buy, i have read that there are different "values"? for different applications, different ohms or something or the other? I am not inclined in these types of things, and I don't want to buy one only to have a compatibility problem. Thanks a lot for the responses guys.

http://www.goldpt.com/info.html

Generally, you want the value to match the input impendance of your preamp. Most tubed preamps are 100k ohm.

Mike B. · « **Reply #13 on:** 16 Dec 2004, 06:46 pm »

Yes, the value of the volume pot is critical. You can contact your preamp manufacture and ask what value comes with it. You might have a control with the info written on it, and a simple visual inspection will do. If you have a ohm meter, you can easily measure this value. You will see three inputs for each channel on the pot. One will be the signal coming in, the middle contact is usually the wiper and has the wire going out to the circuit. The third is the ground. Measure between the two outside posts. That would be input to ground.