[rhys h]

Well, i can either use a simple internal pot, or a external fully blown attenuator with remote control features etc. This was one of the reasons for going external. I didnt want to spend $250 on a volume control that could only be used with one amplifer.

I could allways try with the B1 before i get the b22 panels cut, see what it sounds like and if i dont like it just use a RK40...

 

[adamus]

try it, shouldnt cost much if you have parts for a PS lying around.

 

[rhys h]

Nearly finished it on protoboard, just need to buy the film caps.

 

[digger945]

After recieving a balanced DACT attenuator in the mail today, I think that's what I'm gonna go with inside the amp(these things are much smaller than I thought).
I think if you use a good attenuator inside the amp and keep the wiring as short as possible as AMB states, then you always have the possibility of using something external later if you like and just turn the internal attenuator all the way up(little or no resistance).
This can work the other way also. If you use an external device now, you can always add the internal attenuator later.

^^^This is not my advice, just thoughts.

 

[rhys h]

It is clear there are big advantages and big disadvantages by using a internal or external volume control.

I am going to try the B1 with the Joshua Tree and a remote control pot. There is no way i could fit the Joshua Tree and the remote pot plus logic all inside my beta. If i dont like it, i can get a new front panel for my beta, and add the pot, no big deal.

To be honest, the B1 doesnt really make a diffrence in sound from previous experience.

 

[digger945]

Great thing about Doing It Yourself is you have any number of options and possibilities, and any aspect of your project can be changed any time you like.
I am pretty sure now that my next large amp project will incorporate magnetic TVC/AVC attenuation. I gotta know what it sounds like when it is said " Resistive attenuators, no matter how well made, are always detrimental. But, a well implemented TVC or AVC actually improves drive capabilities as you attenuate."
One thing is for sure, it will be fun finding out.

 

[rhys h]

So true

Im scared about spending a load of money on this external volume control if the B1 is just going to kill the sound of the beta...

 

[vvs_75]

Quote:

Originally Posted by MoodySteve /img/forum/go_quote.gif RK40 will be next-to-impossible to find.

here we go: d-_-b

 

[Fitz]

That's for left-right balance, it wouldn't work as a volume control.

 

[vvs_75]

Thanks for correcting me. Just want to help, I will delete the link.

 

[rhys h]

I was under the impression it was a volume pot aswell, I need to read more carefully next time!

 

[rhys h]

I have made my mind up that i am never going to use a RK27 again. 3 out of 5 i have had now have had problems out of the box. Joshua tree here i come!

 

[rhys h]

I have scrapped the B1 idea. I am going to go with a external passive joshua tree OR stepped attenuator. If there are problems i will change. I dont think there should be a problem with 1ft of cable. Any objections?

R

 

[luvdunhill]

how will you determine if there are "problems"? Just listen and whatever feels right, or will you actually measure things...

 

[adamus]

you could knock up a quick connecting board for the pot, and then try both direct wiring to b22, and then through the extended cable.

using the ears should be ok.