SVT-II

rictified · Post by **rictified** » Tue Jul 12, 2005 3:53 am

Yeah Greg it does sound better, I was a little disappointed though I thought the gain would have been changed. No it's a good sounding head and actually a little cleaner at normal volumes it just seems break up quicker than the Magnavox amps for some reason and the preamp gain is lower, I would guess that is because active basses were around during the late 80's. It has always sounded different than my older ones and it has the same transformers as the Magnavox heads. I guess I just like the heavier thicker sound of the older ones. I'd like to get a 6146B head just to have it and yeah I guess they were rated at 330WRMS, me and you must be reading the same literature, haha! Terry Buddingh (sp?) from bass player mag wrote a good article in Vacuum Tube Valley about them a few years ago.

soundmasterg · Post by **soundmasterg** » Tue Jul 12, 2005 9:20 am

Hey Bob. I've got that Vacuum Tube Valley issue, and yes it was pretty good. My experience with the 6146 heads was with a guy who has since moved to Arizona who had one of them, a Magnavox one, and a later MTI one with 12ax7's and different transformers. My MTI is an early one with the same transformers and has always had the 12dw7's.

Thats odd that the newer one has lower preamp gain with the same circuit. They must have either changed something else in there....some resistor values or something. I would guess that maybe the overall preamp voltages may be lower, which could be changed with a different resistor value in the right place. I don't blame you for just leaving it as it is though...the SVT is complicated to work on.

rictified · Post by **rictified** » Tue Jul 12, 2005 10:09 am

I'm sure there was probably a resister change somewhere, I don't want to change it because it's in pretty nice shape.
The 6146B amps were only made the first year and were Ampeg, Linden NJ amps, Magnavox didn't buy them out until around 1972 I believe. If they were Magnavox and MTI heads they must have been modded. The original 69 heads with 6146B's are going for close to 2 grand now if they are nice. My first one which I bought in 1975 was a 69-70 6550 head with the blue graphics which in earlier Ampegs used to light up, it had blue plastic under a scored template that you put about 300 volts too haha! I think it was inoperable on mine though at least in never worked when I had it. It also had an attached speaker cord with a 4 prong cannon jack like a B-15.

soundmasterg · Post by **soundmasterg** » Wed Jul 13, 2005 9:33 am

What I meant to say about my friend's heads was that he had an early 6146 one that he has since sold, he had a mid 70's Magnavox one, and he had a later MTI made one...probably from around '85 or so. His Magnavox and 6146 ones were completely stock. The MTI one he rebuilt with better caps and resistors, but it had different transformers than the earlier Magnavox era ones, whereas mine has the same transformers as yours. His MTI one sounded different than the Magnavox one, with a bit less power, but it still sounded good. Mine sounded very close to the Magnavox one with the same power level. With the MTI era ones, the really early MTI's like mine used extra American made transformers like the Magnavox ones. At some point they ran out of those and started to use Japanese sourced tranformers, which sounded different and were lower in power.

rictified · Post by **rictified** » Wed Jul 13, 2005 11:48 am

Why did he sell the 6146B head? Did he get a lot for it?

charlyg · Post by **charlyg** » Wed Jul 13, 2005 4:47 pm

Found a couple of V4b's and SVT II's on ebay today. I am monitoring for a possible snipe hit at the end!

soundmasterg · Post by **soundmasterg** » Thu Jul 14, 2005 8:49 am

He needed some money after moving to Arizona. I believe he got over $2k for it but don't know the exact amount.

It had a noticeably more midrange heavy sound and developed more power too. I liked the 6550 equipped SVT's better and so did he.

rictified · Post by **rictified** » Thu Jul 14, 2005 9:19 am

That's what Terry Buddingh said too, I've often wondered if Mel Schacher used one for the red album, sounds like an overdriven SVT.

soundmasterg · Post by **soundmasterg** » Fri Jul 15, 2005 8:47 am

I just used my SVT in the studio on a project and it sounded great! I had the head just outside the control room though so the fan wouldn't get in the recording. I may try putting a resistor in series with one leg of the AC powering the fan to see if it slows the speed down a little and makes it quieter. Something like a 25 w resistor should do the trick, although not sure what value I should use yet. I wonder what the setup is that they use on the new SVT's? Their fans are really quiet.

My SVT sounded better with GE 6550's than with the Svetlana 6550C's, but theres quite a big price difference!

rictified · Post by **rictified** » Fri Jul 15, 2005 9:48 am

I don't know, I bought the 87 brand new as NOS and the fan was very quiet but was blowing out the back instead of in so I reversed it and it was noisy as hell, I put a few washers to back the blades away from the screen and it quieted down some, but it has always been noisy. The 70's fans are very quiet too. Incidently my first, a 69-70 had a Rotron fan in it which had a little plug in the middle and I had to oil it once in a while, that thing was really quiet, never even knew it was on.
I bought a set of Groove Tube GE's during the mid 90's and they sounded great but lasted less than one year and they were biased right, there may have been something wrong with the head, not sure I sold it shortly after like an idiot. though