CVQ STUFF

[germansal]

Hello everybody i want to replace the 3 positions switchs of my 79 series 1 bass,and put a couple of cvq,tell me your opinions and experiences,regards

[serialnumber12]

your filters will give you more when you want it or less if you want it....that's the advantage with CVQ's.....I love mine!

[jazzyvee]

I don't know for sure but I would be surprised if the only thing you needed to do to get CVQ is to change those switches for pots.  
 
I love the CVQ on my S2 bass and like Keavin alludes to it is extremely flexible. My experiences of using CVQ on-stage has been that the acoustics have never been good enough to hear the subtleties when making fine adjustments of the CVQ.
 
However the fixed points of the Q switches on the series I basses are much easier to hear and utilise when you need to change the character of your tone.
 
 
Jazzyvee

[xlrogue6]

As Jazzy said, it's not just a matter of replacing the switches with pots. Strongly suspect your electronics would have to go meet their maker to make it happen.

[count]

The Q-function of the series electronics doesn't come from the 3-position switch.
The only thing the switch does is route the signal via three different circuits which give you the different Q-values.
 
I know there's a guy on ebay selling CVQ pots claiming that exchanging the switch for this will give you series 2 electronics.
That's not the case.
 
Like xlrogue6 says to get this you'd have to send it back to Alembic and have them modify it.
 
I can't imagine a guide to convert your series electronics being posted here on the forum any time soon.
 
(Message edited by count on February 12, 2014)

[fmm]

When I visited Alembic about a year ago, I asked Mica specifically if you could change Series I CVQ electronics to Series II by changing the switch to a pot, and my understanding is that the answer was yes.

[jazzyvee]

If that is the case then why is the difference in the price of  choosing series 1 or 2 electronics basses in the quote generator so great if the difference is  just the cost of 2 pots and a master volume?
 
Jazzyvee

[kenbass4]

Continuous Wood Back plates, Inlaid Logo with Shell, Third Neck Laminate on 4-string, gold Hardware. All standard on Series 2, optional on series 1

[edwin]

When I installed the Series pickups and electronics in my Starfire, the bag of random parts was for a Series I setup. It was fairly trivial to substitute the pots and associated peripherals for the switches. It's a few more parts than just the pots, but if you have a reasonable amount of experience with electronics assembly, it shouldn't be too terribly problematic (I did make the mistake of putting in the wrong value of caps by a couple orders of magnitude creating filters in the Mhz region the first time around).  
 
As far as quick changes on stage, I definitely hear what Jazzy is saying, but with some practice, it's not too out of control. I much prefer the pots to the switches. But I think it also depends on your technique, the music you play and how you expect it to respond. With round wounds, playing finger style or thumb, I don't think it would matter as much as playing pick style on flat wounds. At least, that's been my experience.

[jazzyvee]

Ken bass I was referring to just the cost of just the electronics not the rest of the s2 bits. If you choose a Clarke sig  in the quote gen. Choosing electronics upgrade to Series I  adds $5700 whilst s2 adds $6400 to the cost, so I would be surprised if 3 pots were $700. But I accept my view may be wrong.  
 
Jazzyvee

[rustyg61]

Jazzyvee, I would guess that the circuitry is different on a SII & SI. Open the back plates on your SII & SI & see if you can see anything different besides the pots.

[kenbass4]

Sorry, Jazzy, I thought you were referring to the difference between A Series 1 and A series 2 in the quote generator. Now back to your regularly scheduled thread...

[count]

As edwin says, it involves soldering, caps and resistors. And obviously the switches themselves.
Not everyone are comfortable with messing about with electronics on instruments priced in the 6-10k price range.
 
For those of us that doo however, the mods involved aren't too substantial, but I stress you need to know what you're doing.

[edwin]

My guess is that there's also some fine tuning involved for the CVQ. The switches (if my memory serves) brings in and out various resistors to control the resonant peak. Matching resistors, especially using parts with very tight tolerances, isn't too challenging. But making sure that the sweep of two pots (the frequency pots are dual pots) track properly with the other parts might be a little more challenging. When I rebuilt mine, I used parts I had that were readily available. I'm sure it's not up to the standards of the mothership, as I didn't spend any time matching the parts. Ron spends a lot of time tweaking these things, and this might be one part of the circuit that is susceptible to noise. Any time you are playing with a resonant circuit, it takes a bit of attention to keep everything right where you want it. AKA Just exactly perfect. This is important where a small signal is being amplified many times over, potentially with thousands of watts in front of thousands of people. It's not a complicated circuit, but there are details to get right.
 
I do have a bag of WIMA caps and 1% resistors to rewire my bass with closer tolerances, but I just haven't had the time. I also want to install a master volume. I had a master volume pot around here somewhere, but it's gone walkabout, so that's on hold, too.

[germansal]

I WOULD LIKE TO HEAR MICA S OPINON