Ampeg SVT VR need tech advice

[Wasnex]

Not sure we are talking about the same thing here. Or if there is a language barrier I can’t cross when typing in english. I believe those connectors are called molex. Used in many applications. What I am talking about is when the cords were put inside the female connector. J12. Someone might have put the cord that goes in spot 1 in the spot 2 ande vice versa. A mistake, human error. You can read schematic. Your understanding in that area exceeds mine by far I am sure. What would happen soundwise if that happened? Whould the switch behave backwards so to speak? I can’t tell…

My point is the plug cannot be reversed if it is polarized. Also the plug will not mate properly if pins are accidently crossed, so that is unlikely, especially if it is a Molex.

Also unlikely that someone pulled the pins out of the connector and reinserted them in the wrong order. No idea why someone would do this, however it is possible. Also possible that the plug was wired wrong at the factory. Is this a new problem?


You can buy a Molex pin removable tool, but I have used a jewelers screwdriver.

There are too many options to really say what would happen if some of the pins were out of order. If the operating characteristics have changed, discuss it with the person who worked on the amp. If it's an old problem, confirm the plug is wired properly and troubleshoot the circuit.

 

[r0ddan_swe]

The two channels are more different than alike.

They are. And I am curious to find out if the behaviour of that switch on ch 2 on my amp is doing what it is supposed to do or not… I have seen you in a lot of threads here while searching. My guess is that you have an amp like it. What is that switch supposed to sound like? Is it in the area of the switch on ch 1 or is it completely different?
My mind is that maybe I could create a sound clip or a video where I demo mine. I haven’t got two of these so I have nothing to compare with. And if there is another SVT it’s always a CL. Ch 1 sounds similar to a CL if the master volyme is all the way up on the CL…
I could leave this alone, but I want to know

 

[r0ddan_swe]

My point is the plug cannot be reversed if it is polarized. Also the plug will not mate properly if pins are accidently crossed, so that is unlikely, especially if it is a Molex.

Also unlikely that someone pulled the pins out of the connector and reinserted them in the wrong order. No idea why someone would do this, however it is possible. Also possible that the plug was wired wrong at the factory. Is this a new problem?


You can buy a Molex pin removable tool, but I have used a jewelers screwdriver.
View attachment 4329378

There are too many options to really say what would happen if some of the pins were out of order. If the operating characteristics have changed, discuss it with the person who worked on the amp. If it's an old problem, confirm the plug is wired properly and troubleshoot the circuit.

Wired wrong at the factory is my theory. But I don’t know… no one has tampered with this amp beside changing out a few tubes. My self included. If it’s an old problem I don’t know. I never use ch 2 and normally this amp is in a rehersal studio or on a gig. Never at my place where I can sit around and just play with it. You have done enough thinking about an amp across the atlantic. Very informative posts and I am very grateful, thank you. But I can’t ask for anything more… If I get around to it I might post a clip playing on it while flicking that switch and someone might know if it’s ok or not. If it’s not, I might just leave it alone anyway

 

[JimmyM]

They are. And I am curious to find out if the behaviour of that switch on ch 2 on my amp is doing what it is supposed to do or not… I have seen you in a lot of threads here while searching. My guess is that you have an amp like it. What is that switch supposed to sound like? Is it in the area of the switch on ch 1 or is it completely different?
My mind is that maybe I could create a sound clip or a video where I demo mine. I haven’t got two of these so I have nothing to compare with. And if there is another SVT it’s always a CL. Ch 1 sounds similar to a CL if the master volyme is all the way up on the CL…
I could leave this alone, but I want to know

It sounds to me like a channel they made for guitar, if that makes any sense to you. Less bottom end and all that. The Ultra Hi adds 15 db of 8k on both channels, but the ch 2 Ultra Lo adds 11 db at 40 hz while the ch 1 Ultra lo subtracts 20 db at 600 hz. Of course, those are just the frequency centers, and other frequencies will also be affected around those centers.

 

[r0ddan_swe]

It sounds to me like a channel they made for guitar, if that makes any sense to you. Less bottom end and all that. The Ultra Hi adds 15 db of 8k on both channels, but the ch 2 Ultra Lo adds 11 db at 40 hz while the ch 1 Ultra lo subtracts 20 db at 600 hz. Of course, those are just the frequency centers, and other frequencies will also be affected around those centers.

It does make sense, the guitarr theory. About the adding of the 40 hz, that’s low. That’s what makes my behind buzz while watching a movie. Maybe the frequenzy is of somehow and it ads someting different… if service was free and easily availibly where I live I would for sure have it looked over by someone.
Again about the channel for guitarr theory. Some amps made for guitarr sounds great for bass aswell. There is this sovtek amp I did not buy but had the chance to rehearse some on. Suuuper great. Mig 30 or something. I hade a Marshall super PA. Unreliable but loud as… not sure what it was made for, but sounded great. My Marshall jcm800 was supposed to be a bass amp. A little weak but sounded great. My gitarr player (don’t own him, don’t know how to put it. We play together) have a Marhall super bass, older, that I must try. I bet it sounds great aswell when connected to my cab…. But so far, the ch 1 on this svt of mine is the one I like the most. It’s just fantastic. It reveals every faults I do when I play if I let it, but I’m just an old punkrocker…

 

[Wasnex]

They are. And I am curious to find out if the behaviour of that switch on ch 2 on my amp is doing what it is supposed to do or not… I have seen you in a lot of threads here while searching. My guess is that you have an amp like it. What is that switch supposed to sound like? Is it in the area of the switch on ch 1 or is it completely different?
My mind is that maybe I could create a sound clip or a video where I demo mine. I haven’t got two of these so I have nothing to compare with. And if there is another SVT it’s always a CL. Ch 1 sounds similar to a CL if the master volyme is all the way up on the CL…
I could leave this alone, but I want to know

IMHO...Switch to the left is fairly mid rangey. Switch to the right is deeper and more mellow. Also you may need to run the bass control higher on channel 2 to get similar lows to channel 1.

 

[r0ddan_swe]

I'm opening her up again. What if I put the connector on backwards and just didn't think of pushing it down. My life is full of mistakes, wouldn't be the first time I'm an idiot. I took pictures before removing anything the last time so I will know right away.
If it is me being an idiot, please be nice to me...

 

[r0ddan_swe]

I'm not an idiot, this time anyways... I did record on my phone, but it doesn't cut thru. My ultra low switch on ch 2 works the opposite way around. It's mellow when not engaged and middy and aggressive when engaged (in the right position). Maybe that's why I could get it so cheap =)
Oh well. One of these days I might get it fixed...

 

[JimmyM]

I'm not an idiot, this time anyways... I did record on my phone, but it doesn't cut thru. My ultra low switch on ch 2 works the opposite way around. It's mellow when not engaged and middy and aggressive when engaged (in the right position). Maybe that's why I could get it so cheap =)
Oh well. One of these days I might get it fixed...

I think it's doing exactly what it's supposed to do, so if it ain't broke, why fix it?