New amp day; vintage ampeg v4-b

68Goldfish · #1 09-12-2011, 08:18 PM

Check it out. I pulled this baby off of criagslist for a mere 450$ First of all it looks and sounds to be in great shape. According to the seller it was just gone through by one of the main tube amp guys in this area. I don't know much of the technical side of tube's but it looks like he did the 6550 conversion. I had a later model v4bh and allways regretted selling it because it had such a great sound but it just wasn't loud enough. This amp seems to be considerably louder, in fact I'm having a tough time getting it to overdrive at a lower volume level. I don't know if it has to do with the 6550's. I do know that after playing it for only a half hour or so it was pretty dang warm to downright hot in the back. I guess I'll need to install a fan. Here's some pics.

JimmyM · #2 09-12-2011, 08:45 PM

Nah, no need for a fan. Won't hurt it, but getting hot is what they do. That's half the fun!

That one's a beaut, BTW. Great score!

Bulltrout · #3 09-12-2011, 08:55 PM

Nice! Enjoy it.

rodl2005 · #4 09-12-2011, 09:12 PM

Lucky you! Looks great.

**B-string** · #5 09-12-2011, 09:15 PM

It IS the 6650s that cause it to be harder to get breakup.
I did this with mine.

Fan set to exhaust out the back.

dminer · #6 09-12-2011, 09:48 PM

Great amp and what a good deal. It might not be the KING of tube amps but certainly a PRINCE!!! Enjoy.

68Goldfish · #7 09-12-2011, 11:42 PM

Thanks guys. I notice that there is a sound differance between the two inputs. Two seems brighter to me. I'm used to the differance between chanel one and two on my svt but they have different eq knobs. Not sure why there'd be a differance between the two in the smaller amp. One thing I really like about it so far is that the standby switch is on the front. Doesn't seem like a big deal but it's such a pain bieng in the back of the svt. So is there anything in the 6550 mod that keeps a person from putting the stock tubes back in it other than having to get it biased?

JimmyM · #8 09-13-2011, 12:00 AM

Ampeg 2 channel tube amps have traditionally had a normal and bright channel.

Alex1984 · #9 09-13-2011, 01:11 AM

Congrats! Was this the one in Seattle for $475?

The V4B is a classic amp, and stands up well against any other Ampeg offerings!

maxbass · #10 09-13-2011, 02:34 AM

great conditions
I'd love to have one like that to match my old SVT

68Goldfish · #11 09-13-2011, 07:10 AM

Quote:

Originally Posted by Alex1984

Congrats! Was this the one in Seattle for $475?

The V4B is a classic amp, and stands up well against any other Ampeg offerings!

Yeah, that's the one. Actually it was over on this side of the water near bremerton. The guy even drove twenty miles to delivere it to me at work!

Televator · #12 09-13-2011, 07:17 AM

I want one of these! Do clean examples usually go for the price you paid?

JMac4strngr · #13 09-13-2011, 07:28 AM

Nice score Man! Looks to be in darned good shape. I've found on My V4 that one channel does sound a bit brighter than the other. I don't know the technical reason for it, but It is cool and adds some extra flavor.
On the swapping it back to a 6L6 family tube. AFIAK, it wouldn't be a drop in thing. Probably require some tech time. I believe it invloves changing tube sockets, clips, and re-bias. All in what You wanna spend I guess.

jmpiwonka · #14 09-13-2011, 07:55 AM

nice amp.
i had a v4b like that for a while but it had the 7027 tubes, overdrive on that amp was so nice...just wasn't loud enough for who i play with now. wish i woulda kept that amp though.

also, nice 68 barracuda btw.

tombowlus · #15 09-13-2011, 08:21 AM

Quote:

Originally Posted by JimmyM

That one's a beaut, BTW. Great score!

+1 Very nice!

kosmicwizard · #16 09-13-2011, 10:15 AM

Quote:

Originally Posted by JMac4strngr

Nice score Man! Looks to be in darned good shape. I've found on My V4 that one channel does sound a bit brighter than the other. I don't know the technical reason for it, but It is cool and adds some extra flavor.
On the swapping it back to a 6L6 family tube. AFIAK, it wouldn't be a drop in thing. Probably require some tech time. I believe it invloves changing tube sockets, clips, and re-bias. All in what You wanna spend I guess.

In my MESA/Boogie Bass 400 (non-plus) it didn't have bias pots (because you were supposed to use MESA authorized tubes) I got it with 6L6's in it, but also used 6550's and KT88's to see differences in tone. The plates had less voltage than an SVT, but then again I bet the V4B has less as well. I don't know about 7027 tubes, but the three that I mentioned before all fit in the same sockets. Cheers.

coreyfyfe · #17 09-13-2011, 11:18 AM

Quote:

Originally Posted by 68Goldfish

So is there anything in the 6550 mod that keeps a person from putting the stock tubes back in it other than having to get it biased?

If the mod for 6550s was done properly I think it's just a few resistors in the power section and possibly a bias adjust was installed (mine was done as a trim pot on the board to avoid cutting holes in the chasis). I'd leave the bias adjust if one was added, but swapping back to 7027s shouldn't be much of an issue. They used the same tube sockets, and the only thing really missing would be the tube clamps. I'm not sure what they had on the later 70s amps but the earlier amps had the bear trap style that had to be removed to fit wide-base 6550s.

JMac4strngr · #18 09-13-2011, 11:23 AM

Quote:

Originally Posted by coreyfyfe

If the mod for 6550s was done properly I think it's just a few resistors in the power section and possibly a bias adjust was installed (mine was done as a trim pot on the board to avoid cutting holes in the chasis). I'd leave the bias adjust if one was added, but swapping back to 7027s shouldn't be much of an issue. They used the same tube sockets, and the only thing really missing would be the tube clamps. I'm not sure what they had on the later 70s amps but the earlier amps had the bear trap style that had to be removed to fit wide-base 6550s.

This is what I was thinking of. My V4 is the early 70's version, so these mods were what the tech told Me would have to be done to convert to 6550's....

**B-string** · #19 09-13-2011, 07:18 PM

Quote:

Originally Posted by 68Goldfish

Thanks guys. I notice that there is a sound differance between the two inputs. Two seems brighter to me. I'm used to the differance between chanel one and two on my svt but they have different eq knobs. Not sure why there'd be a differance between the two in the smaller amp. One thing I really like about it so far is that the standby switch is on the front. Doesn't seem like a big deal but it's such a pain bieng in the back of the svt. So is there anything in the 6550 mod that keeps a person from putting the stock tubes back in it other than having to get it biased?

Early 70's units had the screen resistors changed. Not a big deal, but it won't sound or respond quite right without changing them back.

jumbo_steelie · #20 09-13-2011, 07:49 PM

Nice!!! She looks just like the one I picked up awhile ago. I haven't noticed any difference between the inputs, but I'll definately give it a shot tomorrow....