How does the V4-B Reissue Stack Up?

I've never had a vintage V4B, but have had the re-issue and both an SVT-VR and early 70s Blueline SVT.

The re-issue sounds incredible, especially through a bigger cabinet. Plenty of power to stay clean when I needed it, but get a little grindy when I wanted it. Very simple to operate and dead quiet (no fan noise, no hiss). Bulletproof too - I never had an issue with mine.

To my ears, it was a little sweeter sounding than my SVT, but lacked a little "weight" behind the notes in comparison. A great rock amp.

 

^^ This ^^
100% agree. My V4B sounds great through my assortment of Ampeg cabs.
(2x svt210av, 70’s V4 4x12, and flatback 810).
Do it: you won’t be sorry.

 

I totally agree with Alexander and CTBassGuy! The V4B Reissue is an AWESOME amp!!! I run mine with 2 SVT 212AV cabs and IMHO it just doesn't get any better than that.

 

I can't say enough good things about my V-4B. I also run it though a variety of Ampeg cabs and it is especially magic when going through my 2x112AV. Had a rehearsal last night in a new rehearsal room where they had a V-4B through one of the 212AV and it kills, even compared to the Ampeg 410 cabs in the other room we usually use. There's just something about having power tubes and I'd love to haul around an SVT with a 610 or 810, but a V-4B into a pair of 12s is the best sounding, most practical set up for me.

 

Plus one. I got myself a V4B last holiday season, along with one of the 2x12 cabs. Zero complaints, sounds awesome.

 

Anything through an 810 is loud and sounds wonderful. Without having tube experience as you described, a new amp with a full warranty beats a used one any day.

 

Yep, from experience...
Gain was at 10 o’clock, Master at 3 o’clock and the knob on my bass was at about 4 (of 10). I could have gotten so much louder...

 

The bass amps and bass cabs are designed to take the low end frequencies, don’t worry about that.

The reissue V4B is layed out well and is designed to be repaired. The tubes are all readily available, same as those used for guitar amps such as the 12AX7 and 6L6GC. The difference is a beefier power supply that has the capacity to deal with low frequencies. Of course the EQ is optimized for bass. I would look for one of those used.

The vintage V4B is another story. Of all the Ampeg amps, I find that they take the most work to bring up to spec. These amps can come with a lot of difficult issues that need to be addresssed. It helps to have test equipment and experience working on them. Part of the issues stem from the amps running very hot. It takes a toll on components, shielded wires, and solder joints. The 70’s era PCB were also not the best. Lifting traces are not uncommon when compontents have blown. Cleaning the inside well can take time, there are a lot of tight spaces. There are reissue power tubes available. One tube, the 6K11 is getting expensive, you have to go NOS. The amp also uses 12DW7 tubes. Not common off the shelf tubes, often they have to be ordered.

Having said that, if you can find a good vintage V4B that has been properly serviced and comes without a lot of modifications, you will have a fantastic amp.

Doing the work yourself makes all the difference in terms of costs. Still at the end of the day, parts costs add up. A reissue V4B wouldn’t need any work other than maybe a cleaning and perhaps new tubes.

Can’t comments on the SVT3-pro other than to say that they can come with issues as well. It has a transistorized power amp, I prefer tubes.

 

Lemme tell you... I have owned so many amps over the years. Lots of them have been mid range to expensive. The only one I have EVER regret selling was my v4b reissue. It was a great amp period. Bass or guitar. Plug in and smile. The best thing about having only 100 watts is how easy it is to get natural grind. There is magic when you get the poweramp tubes pumping in any tube amp. All these high wattage class d amps today simulate it but its not the same.

 

I MUCH prefer the V4B. You can get a decent, usable tone out of a 3PRO, but nothing great. Basic meat and potato bass tone. There are a bunch of Class D heads that crush it IME in terms of tone and features - the 3PRO is a bit of a relic.

The V4B just sings. And I love the dynamics you can get out of it. Getting a great tone out of it is just a matter of turning the thing on. Through an 810, it sat perfectly with a loud rock band. I sold mine and sometimes regret it. I just ultimately preferred the SVT, so that got all the airtime...

 

What is the sense of making it so you can't adjust the Bias without taking the head to a tech? Fender has an autoBias system that works great why didn't Ampeg come up with something like that or at least do what they have in the past and put test points and pots where they are accessible. If I want to change tubes it will cost me at least another 100.00 or more to get a tech to bias it. That is the major hold up to buying this amp for me. I guess that would put a stop to power tube rolling.

 

Fenders autobias roll out was shaky and caused a lot of failures in the early 100T amps. Traynor removed the autobias from the YBA-200 when they updated to the 200-2 circuit because it was more trouble than it was worth.

I do think an external adjustable bias like the one on the SVT or PF tube amps would have been a good option to have included on the V4 though.

But learning how to properly bias your amp is worth it if you plan to regularly use a tube amp, the led bias systems on the other ampeg amps are a “close enough” measure and not super accurate. That said, power tube rolling doesn’t really seem a good use of money or tubes. Differences are going to be fairly minimal when properly biased. You’ll get more variation with preamp tubes.

 

So does it have Bias test points and adjustments inside that are safely accessible to the average Joe with a general knowledge of electronics and a Meter? Or is it a tech only deal? And thank you for the information . You are very helpful.

 

I had the original model for something like 30 years.
Bought it used and never even so much as changed the tubes; guess I was lucky as it was super reliable.
It was one of the best sounding amps I've ever owned and I liked it better tone wise than my SVT-CL.

@beans-on-toast how different does the new one sound with 6L6's compared to the original with 7027A's?
Are the changes all for the good or is there a difference in tone?

 

Official V4B biasing instructions.

 

It has been posted by ampeg and others there is a pot in the new reissues, I haven’t opened one up myself, but it’s a fairly easy task to add one if there isn’t. I’ve done that on my vintage V4s. The easiest and least risky method for checking bias on any tube guitar/bass amp would be to get a bias probe which can read plate voltage and current. Euro tubes makes their probe one, its around $100, and plugs in line with the power tube with little digital readout displays. They’re apparently out of stock on their website awaiting a redesigned layout for release sometime in July, but you can find them available elsewhere. Bias Probes and Multimeters - Eurotubes Inc.

There are cheaper probes for just cathode current which can be attached to a meter, but that also requires reading plate voltage manually. A little more risk of touching things you shouldn’t be touching but with some patience and practice a skill you can learn.