Versatone pan o flex copies.... Are they there?

[Muziekschuur]

Thank you... I will hunt something like that down... But now I allso can make one...

 

[Muziekschuur]

I do believe it was used in Hot Tuna... Cassidy still uses that amp...

 

[christw]

I've seen them around and they're rare. You'd put at least as much into purchasing and restoring one of these amps as building your own. I say DIY it up.

 

[edwinhurwitz]

Using a simple tube pre and Dynaco ST 70 bridged mono and cranked into a single low watt Jenson style speaker will get you the same kind of overdrive....won't it? Or any tube old stereo that has bridging to mono capability.......I used to practice through a Harmon Kardon stereo with 7591's and get that kind of flower power overdrive for giggles.....

I had this idea that the Versatone was unique in that it was biamped and then the signals were combined in the output transformer. So, you could get the highs and lows each with their own brand of growl and grit and output tube crunch. The schematic that was posted here looks sort of like that, although it's not clear to me exactly what's going on past the output tubes.

 

[Jeff Scott]

Is that schematic that was posted of Jack's actual amp showing mods done to it? His name (spelled incorrectly!) is written in pencil at the top of those schematics.

 

[fdeck]

I read every schematic that comes along, because I'm curious about this stuff. And I've got to say, I thought by now that I'd seen everything. That's one weird puppy.

 

[wagdog]

So now we just need someone to build it and tell us what it sounds like.

 

[teemuk]

I had this idea that the Versatone was unique in that it was biamped and then the signals were combined in the output transformer.

Instead of combining the bass and treble band outputs of a generic "James" tonestack the amp splits those bands to two different power amps.

No, the signals do not combine in an output transformer. There are two output transformers, one for each power amp and their outputs simply run to a "makeshift" socket, typical for the times. The socket in turn connects to two different speakers (one for each amp) and at least one of those outputa is also treated with a LC filter for further and finer "crossovering purposes".

Here you can see the two output transformers side to side (you can easily see which one is for bass amp and which one for treble), the "tube socket" style speaker jack / plug in between them and in the bottom pic the two speakers for bass and treble bands.

As I said earlier, aside from being a bi-amp and having a sort of ingenious method to create the X-over network in the preamp this is a very generic design with very generic circuit architecture. The Dynaco reference is likely pretty much on point. I think one could easily mod a Dynaco stereo amp to perform quite identically but the matter that in the last few decades no one has really shown much interest to introduce such designs to markets speaks volumes.

IMO, most of the "excitement factor" of these kinds of things is usually based on being something used by some moderately famous artist (who likely used tons of other gear as well), being rare, and being vintage. Pitted against modern competitors such things, however, usually end up being a sort of dissapointment. Based on the size of those transformers and speakers, not to mention apparantly low output power rating, I'm sure I would not want this thing as my bass amp, at least not the main one. As a discussion-inducing showoff piece to fool around with occasionally, why not.

 

[MAMMOTHvolume]

check out some of the hammond amps, i have one with seperate outputs for high mids and lows

 

[teemuk]

check out some of the hammond amps, i have one with seperate outputs for high mids and lows

Gibson experimented with this too. They also had a gargantuan-size self-powered cab with eight 12" speakers and four separate power amps inside it.

 

[BassmanPaul]

I read every schematic that comes along, because I'm curious about this stuff. And I've got to say, I thought by now that I'd seen everything. That's one weird puppy.

It really is a simple design. Back in the day, OPTs were pretty small and unable to handle much power. Some amps doubled up on the output stages and so used two OPTs. Then the secondaries were added into the load. There were a lot of ingenious ways to get more power. After "real" OPTs became available they faded into obscurity.

 

[chadds]

What knowledge? Aside from being an early pioneer of bi-amps the Versatone was a pretty generic tube amp.

Obviously not.
Don't ever forget that we are here making music, whatever it takes.
Jack is a talented bassist. If you are of the engineering perspective, be humble, try to hear what we hear and help us with your great knowledge to make that music. Okay?

 

[edwinhurwitz]

Obviously not.
Don't ever forget that we are here making music, whatever it takes.
Jack is a talented bassist. If you are of the engineering perspective, be humble, try to hear what we hear and help us with your great knowledge to make that music. Okay?

I think you guys are more in agreement than you might think. The common agreement is that Jack is a talented bassist. It might be that the glory of that sound has more to do with the Jack than any secrets in the Versatone circuit or parts. It might be well worth it to try the Versatone recipe with another rig to see what happens. One way would be with an Alembic SF2, which can be used as a crossover as sorts, into a stereo low watt tube amp into a couple of appropriate speakers. There are also other ways to try this out. It's the idea more than the implementation that is key here. In the era of the Versatone, amp designers would often take things right out of the tube manufacturer application books (which are still available) and use cheap off the shelf parts to build them. Lots of classic and cool amps came into being this way (Fender comes to mind) and there's no reason Versatone would be any different. I don't think anyone is holding out on us.

 

[fdeck]

It really is a simple design. Back in the day, OPTs were pretty small and unable to handle much power. Some amps doubled up on the output stages and so used two OPTs. Then the secondaries were added into the load. There were a lot of ingenious ways to get more power. After "real" OPTs became available they faded into obscurity.

That's interesting. Thanks!

 

[MR PC]

Jack in action with the Versatone early on, 1970.

 

[pgk]

a friend owns two Versatone Pan-O-Flex amps, one is a restored full working unit and the other the guts and speakers but no cab. the amp sounds out of this world, it is utterly unique in the bass world to this day. OH the clean tone of a properly restored Versatone! they were sort of the B15 equivalent in california studios back in their day, just not as plentiful. and like the mighty B15 their tone is one of a kind. plenty of useable volume for drummer-less acoustic gigs, it is my bud's rig of choice for those situations. and it has a grind when it's wound up that would make a V4B blush and run for cover, you'd have to hear it to believe it. full band live gigs? no problem, you simply mic it up, but you must mic both speakers. speaking of speakers, the original 12 they came with was a very shallow frame Utah and they are extremely hard to find. they're a big part of the mojo, much like the square magnet CTS 15's are for B15's

 

[pgk]

here ya go, with a very thorough description:

Link Removed

 

[edwinhurwitz]

here ya go, with a very thorough description:

Link Removed

I liked all of that except for the price!

 

[mellowgerman]

I realize I'm three months late here, but contrary to popular belief, Jack's Versatone only had a single 12" speaker as opposed to Carol Kaye's which had two.
Here's a pretty informative link with a lot of the variations that were available... if you scroll down a bit you'll find that there were single-speaker versions
[Invalid or Expired Link Removed]

 

[billsundt]

That is my copy of the Versatone schematic. I serviced Jack's amp when working for Soldano Custom Amplification and noted the details. I have built two clones, the first for Dan Schwartz, and had planned to make more. I still can if anyone is interested.