My new V-4 and questions

[StuartV]

I just won this V-4 on eBay. It is listed as a late 70s Magnavox era.

Ampet VT-22 V-4 All Tube Made in USA Magnavox Guitar Amp | eBay

Questions:

1) $377, shipped seems like a darn good price, yes? Is there something about this one that I didn't catch that made it go for so cheap? Or is it maybe just that the listing title said "Ampet" instead of "Ampeg", so some folks that might have bid on it missed it in their searches?

2) I read all I could find here on TB about the differences between the V-4 and V-4B. One thread had info about 3 capacitors that are different in the input section that provide a low frequency roll-off. According to the poster of that info, the V-4 rows off the low end about 10 Hz higher than the V-4B. Other folks posted that this doesn't seem to make any significant difference to the sound, but they seem to be posters who play 4-stringers. Can anybody comment on whether this would be more of an issue when playing a 5-string through it?

3) If I take it to a good tech to have the capacitors on one of the input channels changed over to V-4B specs (which, as I understand it should just be 2 caps), about how much should I be prepared to pay for that? I'm guessing 1 hour labor and a dollar or two worth of parts?

4) In the stock amp, is there any difference between the 2 input channels? If not, why does it even have 2 input channels? Is there a reason to ever use both when using the amp for bass?

5) Is there a "recommended" list of modifications that I should consider for using the V-4 for bass? It appears to already have a 3-prong plug. Should I:

- change both input channels to V-4B specs? Change one and leave the other stock (though that would still mean changing one cap that is common to both), so it would still have full re-sale value to guitar players?

- change both inputs to V-4B specs and have one modified to have a -10 or -15db pad for use with an active bass?

- change the polarity switch to do something else (since I assume it's superfluous with the amp having a 3-prong plug on it)? If so, what?

- leave it the fark alone and just go play, dummy?

Thanks in advance for any help!

[JimmyM]

I'd put that head at 73 or 74. The later ones had a redesigned face plate.

1. Brilliant price.

2. First I ever heard that but it could be true. I seriously doubt it would make much difference since the cabs we used back then (and some of us still do) rolled off lows at a higher point than the head.

3. Probably aren't far off. Wondering why you'd do that, though.

4. One is normal, one is bright. Been so long since I had a V4B that I forget how it works, but that much I remember from having one.

5. Leave it the fark alone and just go play, dummy You have no clue how it sounds yet. Don't make mods just to mod it. Save your money and just enjoy one of the best bass sounds you could hope for.

[coreyfyfe]

Originally Posted by StuartV

1) $377, shipped seems like a darn good price, yes? Is there something about this one that I didn't catch that made it go for so cheap? Or is it maybe just that the listing title said "Ampet" instead of "Ampeg", so some folks that might have bid on it missed it in their searches?

Great price.

Originally Posted by StuartV

2) I read all I could find here on TB about the differences between the V-4 and V-4B. One thread had info about 3 capacitors that are different in the input section that provide a low frequency roll-off. According to the poster of that info, the V-4 rows off the low end about 10 Hz higher than the V-4B. Other folks posted that this doesn't seem to make any significant difference to the sound, but they seem to be posters who play 4-stringers. Can anybody comment on whether this would be more of an issue when playing a 5-string through it?

You'd probably barely notice a difference. I used a V4 for a while with both 4 string and 5 string basses, active and passive, and it handled them all very well.

Originally Posted by StuartV

3) If I take it to a good tech to have the capacitors on one of the input channels changed over to V-4B specs (which, as I understand it should just be 2 caps), about how much should I be prepared to pay for that? I'm guessing 1 hour labor and a dollar or two worth of parts?

You could have the channels modded, it would probably cost about $60 with parts and labor. Again, totally not necessary IMO. More important will likely be a check of all solder joints, etc, after shipping and possible cap job (should be in the $100-150 range for this amp) if the old caps are nearing the end of their lifespan.

Originally Posted by StuartV

4) In the stock amp, is there any difference between the 2 input channels? If not, why does it even have 2 input channels? Is there a reason to ever use both when using the amp for bass?

I noticed more perceived volume on channel 2 with my V4, but that would probably be consistent with channel 2 being a bright channel (less lows for more perceived volume). Otherwise they were the same. At one point I used my amp as a two channel with an A/B switch so I could run my scrambler pedal full out and not have to worry about volume shifts, but I eventually changed my setup and just stuck with channel 1.

Originally Posted by StuartV

5) Is there a "recommended" list of modifications that I should consider for using the V-4 for bass? It appears to already have a 3-prong plug.

Nope, just plug and play. Some amps over the years were changed to use 6550s (and rarely EL34s) when 7027s went out of production, but that's really just a taste issue. The different power tubes don't give you any real change in output, just a slight change in tone, and the current draw of 6550s can be harmful to certain power transformers in the long run if the transformer is running hotter.

[RutherfordBrave]

I was watching this auction as it ended -- you got it for a sick price! I've been watching them for a long while, and I'm now convinced that I need to flip the one "spare" amp I have in the stable to have the funds for next time one like this comes around. Hope it's as good as advertised!

[StuartV]

Originally Posted by JimmyM

I'd put that head at 73 or 74. The later ones had a redesigned face plate.

1. Brilliant price.

2. First I ever heard that but it could be true. I seriously doubt it would make much difference since the cabs we used back then (and some of us still do) rolled off lows at a higher point than the head.

3. Probably aren't far off. Wondering why you'd do that, though.

4. One is normal, one is bright. Been so long since I had a V4B that I forget how it works, but that much I remember from having one.

5. Leave it the fark alone and just go play, dummy You have no clue how it sounds yet. Don't make mods just to mod it. Save your money and just enjoy one of the best bass sounds you could hope for.

Ha ha! That's pretty much what I expected to hear. Thanks for the info. I thought, from my reading on here, that it looked like it was older than "late 70s". Is Magnavox-era considered "good" or "not as desirable"?

The main reasons for thinking about modding the input channels are, one, I'm planning to take it to a local tech that seems to be really good and have him give it a check-up before I even turn it on. The eBay listing said the tubes are "older" and "a fresh set of tubes might need to be installed in the near future". Between that and whatever could happen to it in shipping, getting an immediate physical seems like a good idea. My thought is that, given what it's already going to cost me for that check-up, having him swap out 2 or 3 capacitors on the inputs would probably increase my bill very, very little.

Plus, my thought was that 10 Hz difference in the roll-off point might not matter on a 4-string, but that's just about the difference between a low E and a low B, so I was thinking that it could make a noticeable difference with a 5-string.

And since I can probably get the mod done for very little extra cost, I was really just wondering "why NOT do it?"

[I<34080]

Anything pre SLM Ampeg is considered desirable. With that said, any era of all tube Ampeg is considered desirable.

[StuartV]

The info on the difference in capacitors between the VT-22/V-4 and the V-4B is here:

stonemarmot.com/rants » How To Make The Ampeg V4 Better For Bass Guitar

And the guy who wrote that says:

The change isn’t dramatic ... but it does improve the clarity of the lowest four or five notes on a four string, standard tuned bass guitar.

[mikerophone]

i think that's early 70s, rather than late. ampegv4.com has lots of handy info if you haven't looked there yet. either way, you got a great deal. the v4 is awesome! i never did the cap mod on mine, i thought it sounded fine as is. also, i never noticed a difference between the two inputs. i remember one time i used a boss tuner to split my signal, ran clean into one input, and distorted into the second. that was fun to play with.

[Alex1984]

Yeah. Early 70s, love those aluminum knobs, look so classy. The stock V4 sounds fantastic on bass. While I do use the ultra-hi and ultra-lo on my SVT, I don't like how the V4B's ultra-lo works, I think it muddied up the sound rather than tightened it. It made the sound very flabby. So I don't miss the V4B's ultra-lo functionality at all.

[StuartV]

Originally Posted by coreyfyfe

Great price.



You'd probably barely notice a difference. I used a V4 for a while with both 4 string and 5 string basses, active and passive, and it handled them all very well.



You could have the channels modded, it would probably cost about $60 with parts and labor. Again, totally not necessary IMO. More important will likely be a check of all solder joints, etc, after shipping and possible cap job (should be in the $100-150 range for this amp) if the old caps are nearing the end of their lifespan.



I noticed more perceived volume on channel 2 with my V4, but that would probably be consistent with channel 2 being a bright channel (less lows for more perceived volume). Otherwise they were the same. At one point I used my amp as a two channel with an A/B switch so I could run my scrambler pedal full out and not have to worry about volume shifts, but I eventually changed my setup and just stuck with channel 1.



Nope, just plug and play. Some amps over the years were changed to use 6550s (and rarely EL34s) when 7027s went out of production, but that's really just a taste issue. The different power tubes don't give you any real change in output, just a slight change in tone, and the current draw of 6550s can be harmful to certain power transformers in the long run if the transformer is running hotter.

Thanks for that info. It's definitely good to hear somebody using one with a 5-string and liking it as it is. I generally like to keep things stock. And the tech I will take it to has a rep for trying to keep things stock and only replacing parts that NEED to be replaced. So, I guess we'll probably just leave it alone (dummy! ).

[StuartV]

Originally Posted by mikerophone

i think that's early 70s, rather than late. ampegv4.com has lots of handy info if you haven't looked there yet.

I did look there, but that site says it's specifically about late 70s models. I'm not sure what the differences really are, so I'm not sure how much info there is actually applicable.

[StuartV]

Originally Posted by Alex1984

Yeah. Early 70s, love those aluminum knobs, look so classy. The stock V4 sounds fantastic on bass. While I do use the ultra-hi and ultra-lo on my SVT, I don't like how the V4B's ultra-lo works, I think it muddied up the sound rather than tightened it. It made the sound very flabby. So I don't miss the V4B's ultra-lo functionality at all.

I also have an SVT 2 Pro, and I don't use the Ultra Lo, Ultra Hi, Bright, or Graphic EQ on it. So, I imagine I'll be perfectly happy with the V-4 with no Ultra Lo switch on it.

[BassmanPaul]

Stuart, I'll second Jimmy's comments, leave the amp as designed. You're not going to hear much if any difference with a 10Hz change. The fundamental is not where the power is on a bass it's all the harmonics. A lot of folk who modify equipment report improvements that may be there or may not. Folk hear what they want to hear be it real or imagined. There are a lot of players playing through these amps quite happily using four, five and six string basses.

[sonicvi]

Looking at schematics for the V4 and V4B and I don't see any difference at all between the channels. Any difference in gain could be due to component tolerance or difference in the channels' tubes. It'd likely be a pretty small difference though.

[StuartV]

You mean you don't see any difference between Channel 1 and Channel 2? Yeah, as far as I can tell from all my reading and looking at scans of Ampeg literature from back then, I don't think there is a difference. The SVT (and some other Ampegs, I think) had stacked input jacks, so there were 2 for each channel, where one was Bright and the other Normal. But, the V-4(B) appears to just have 2 separate channels with no Bright or other difference between the two.

I suppose it could be useful if you set the input sensitivitys and volumes differently and then used an A/B switch. You could switch between a cleaner sound and a crunchier sound but keep the overall volume the same. Or switch between a lower volume level for accompaniment and a louder volume for solos or something.

[sonicvi]

Originally Posted by StuartV

You mean you don't see any difference between Channel 1 and Channel 2?

Right, between the channels, not between the amps.

[whitespike]

Not to hijack the thread, as this is V4 related, but what are the things to consider if you want to get the most "clean" headroom out of your V4? I actually love the way mine sounds, but it's just barely too dirty at live volume. It's passable, but I wish I could get one more inch of clean headroom.

I'll be reporting back with my tube selection soon...

[nashvillebill]

Originally Posted by whitespike

Not to hijack the thread, as this is V4 related, but what are the things to consider if you want to get the most "clean" headroom out of your V4? I actually love the way mine sounds, but it's just barely too dirty at live volume. It's passable, but I wish I could get one more inch of clean headroom.

I'll be reporting back with my tube selection soon...

Make sure the amp has been completely serviced: all old electrolytic caps MUST be replaced. If the power supply caps are getting old, B+ will sag and the amp will lose headroom.

Efficient speakers are also important, some speakers are incredibly inefficient.

[whitespike]

Originally Posted by nashvillebill

Make sure the amp has been completely serviced: all old electrolytic caps MUST be replaced. If the power supply caps are getting old, B+ will sag and the amp will lose headroom.

Efficient speakers are also important, some speakers are incredibly inefficient.

I'm using four 12s: Eminence 12A II's. Mine has been serviced and retubed but I think has original caps. DO you think that is the deal?

[RockBobby]

Originally Posted by nashvillebill

Make sure the amp has been completely serviced: all old electrolytic caps MUST be replaced. If the power supply caps are getting old, B+ will sag and the amp will lose headroom.

Efficient speakers are also important, some speakers are incredibly inefficient.

+1. Also, don't get sucked into a whole tube change unless they are newer cheap tubes. Mine has 1982 USA tubes in it and going strong!!!
No need to mod the tone circuits. It's a plug and play amp for sure. Just adjust your tone controls to taste.