Ampeg V4 vs V4B

[TheRhealDeal]

Can anyone help me understand the difference between these 2 heads?

I have been wanting to get a V4 to go with my Ampeg V9 for some time but I want to make sure I'm getting the right thing.

Thanks!

 

[77PBass]

reverb

 

[TheRhealDeal]

That's the only difference? That the v4 has a reverb knob and the other doesn't?

What about master volume vs no master volume control? Is this a variation of the same amp?

 

[77PBass]

V4

V4B

Different eras but you get the point. The VT22 is basically a combo version of the V4.

 

[coreyfyfe]

Master volume was added to the post-1975 versions of both. In the late 70s the V4 also got a distortion knob. The V4 has sensitivity switches on the inputs and no bass boost, the V4B lacked the sensitivity switches and had a bass boost. The V4's mid frequency selector was 300/1K/3K, the V4B is 300/800/2.5K. As said above, the V4 also had reverb.

 

[77PBass]

Opps...forgot input sensitivity on the V4.

 

[77PBass]

Master volume was added to the post-1975 versions of both. In the late 70s the V4 also got a distortion knob. The V4 has sensitivity switches on the inputs and no bass boost, the V4B lacked the sensitivity switches and had a bass boost. The V4's mid frequency selector was 300/1K/3K, the V4B is 300/800/2.5K. As said above, the V4 also had reverb.

The bass boost switch acts as a LPF and is almost useless.

 

[TheRhealDeal]

Thanks, been a huge help! Any thoughts on which one would work better with my V9? And would 100w be enough to power it you think?

 

[Sunnburn]

The bass boost switch acts as a LPF and is almost useless.

Damn, I use it and love it. Although, I biamp with my cleans (V4B, Ultra low)through a 2x15 and My effects (Peavey VB-2) through a 2x10. No low ends loss from pedals!

 

[nashvillebill]

V4

V4B

Different eras but you get the point. The VT22 is basically a combo version of the V4.

hey that particular V4 looks mighty familiar !!!

 

[77PBass]

I said almost. I read somewhere people used V4B and the bass boost in bi-amped PA situations way back when in the days of Edison.

 

[coreyfyfe]

The bass boost switch acts as a LPF and is almost useless.

Agreed. The bass and high boost switches just cut from your mids. I find the normal EQ knobs to be enough for me, but if people like them and that's their thing, that's cool too.

 

[dannylectro]

I always preferred the V4 to the V4B back in the day... both had great bottom, but the V4 was able to dial in a little more "bite".

 

[Grey Sarcasm]

Never used a V4. I know that the V4B puts out some massive power. Running it through a Marshall JCM bass cab gets some serious grit. I'd imagine the V4 would do the same. Killer sound!

 

[Tuned]

The V4 has a higher cutoff at the input bias, doesn't reach as deep. You can easily mod it and apart from the different controls the amps are pretty much the same. By adding a reasonably inexpensive power transformer to provide more current to the heater filaments you can use 6550 power tubes (like the SVT) to up them to ~140W. I also recommend getting a master volume control and run the preamp pinned, gets a great grit. This can be done without modifying the amp, just wire a 500k volume pot to a cable with 1/4" jack, plug it into the preamp out on the back, and it's a master volume in reverse - off it does nothing, as you turn to the right it slowly shorts the preamp so less signal passes to the power amp. Don't recommend running it fully shorted for very long. You can also pull two power tubes (the outer ones or the inner ones) and switch the impedance to half what the cab actually is and run it at half power. You get that slammed power amp tone without any chance of blowing anything. Can't do that with an SVT!

 

[StuartV]

The V4's mid frequency selector was 300/1K/3K, the V4B is 300/800/2.5K. As said above, the V4 also had reverb.

At least on the early 70s models, the mid frequency selector is identical between V4 and V4B.

The only difference in the circuits is the reverb on the V4 and 3 capacitors in the input section which slightly raise the frequency of the low end roll off in the V4. I had my Channel 2 on my V4 modified to V4B specs and I really can't tell any difference. That involved changing 2 capacitors, 1 of which is shared with Channel 1, so technically my Channel 1 is also modified slightly from original. But, I would challenge anyone to hear a difference in Channel 1 from changing that 1 cap - whether you're using guitar or bass.

 

[StuartV]

And if you want Master Volume, you don't have to mod the amp at all. Get an original Ampeg Master Volume plug-in switch (if you can find one), or get a repro from Fliptops, or an improved version from Baja Tech. I have the Baja Tech and it works well. The Baja one has a 1/4" jack on it, so you can use whatever length cable you want. The others have a cable which is permanently attached to the footpedal and very long. I set mine on top of the amp, so the cable only needs to be about 2' long, so I didn't want one of those others.

They all just plug into the Ext Amp jack on the back of the V4 or V4B.

http://www.bajatechcustom.com/catalog/index.php

http://www.fliptops.net/catalog/p-100825/master-volume-pedal-for-v-sereis-and-others.-deluxe

 

[deanamite]

Hi everyone
As usual I'm a little late to the party. I recently bought a V4 and I'm in love. I use it as a guitar amp and it has the exact sound I need. After all this JCM 800, JMP 800, Fender Bassman 100, Ampeg V7 etc. business I have finally found my amp!
Which leads me to my question. I am looking for an original faceplate for the flip switch version and for a rectangular original Logo. Superficial, preliminary research on ebay and fliptops.com has not yielded any results. Does anyone have any leads? I'm also interested in the original knobs.
Thanks to anyone who replies