Sending up a little smoke signal on this one
For sale is my main head for the past 1 1/2 years, my Ampeg V4B. Got an SVT-CL on the way and I'm moving 900 miles end of the month, so something's gotta give. If money wasn't tight (student loans) and I didn't have to haul my life in a mid-sized sedan, she would not be going anywhere!
She's been a workhorse for countless players for the past 30-some years. I used it for something like 40 on-stage events; I haven't used it so much in the past 3 months (haven't been playing much - I moved to a very isolated area and there's not many outlets for a lowly bassist).
The Good: It is in excellent shape! All-original that I can see except for a small hole in the faceplate, two different (ahem...ugly) knobs, and 3-prong cord. I don't know what the hole was for - probably a mod, but I don't know if they ever carried it out. If there is a mod, it does not affect any of the knobs as far as I can tell. Built like a tank; tolex has some light wear spots on the front edges and a few small tears but overall I'd say it's a bit better than average for its age. Faceplate is clean; metal corners/parts have some light rust/pitting but just nominal. All switches/knobs work, pilot lights work perfectly. The tone is AWESOME! Lots of headroom! Lots of vintage versatility for the value.
The Bad: It needs a good servicing. I purchased it and it rolled with me quite cleanly for over a year. Then, it started to lose volume intermittently. I would flip the standby and it would fix itself. Get a little popping when I did that. I've read it is merely a preamp tube issue. I never played it on stage at this point and it was residence practice amp. I made the decision I wanted an SVT so I never felt the need to put money into it and clean it up. Still haven't taught myself how to bias/service one either

The small hole in the faceplate and the ugly knobs are both negatives as well - but otherwise, it's just your average 70's V4B in the physical respect. The tubes in it are a smattering - two JJ 7027's, two GE 7027's, and various preamp tubes. the 6K11 looks like it's the culprit for the issue that the amp has. If anyone thinks this is a more advanced issue than a tube replacement, let me know so I don't pull one over on anyone!
I think I covered it all. I've really enjoyed this amp and would be 100% cleaning her up, but she was merely a vessel to something I am more interested in. Looking to get $600 or B/O shipped to New England (I'm actually in Maine at the time, temporarily) and Mid-Atlantic, $610 to Deep South and Mid-West, and $620 for Rockies and West Coast. Thanks! Let me know if you have any questions.