Ampeg B-25

I always wanted a great all tube bass amp for my studio and this amp kinda fell into my lap when I least expected. Love when that happens. First I found a late 60's Sunn cabinet with a single 15" JBL E-130. It's closed back and ported in the bottom corner. Looks like a blackface fender and I got it for $40 at a pawn shop. A month later my friend gave me his fried Ampeg B-25 head that he had in highschool. I put it up on my bench and found a long list of problems with it. No wonder you can pick one up cheap...they almost all need work. Looks like the power supply section went down when the rectifier failed. To make a long story short, I gave the amp a full re-tube, a full electrolytic cap job, rebuilt the power supply (a couple burned power resistors and a diode), added a grounded power cable, and rewired the speaker jacks so that I had an 8 ohm and a 16 ohm out off the output transformer. Also did some work to the head cab (put large rubber feet on, replaced the bolts that fasten the amp inside the cab, and repaired the cloth covered front panel). Got all the parts from fliptops.net Well, all of this work paid off. This 4 input, two channel, 55 watt bass amp is fantastic. I like channel 2 with the normal input best with my fender jazz bass.

Mmmmm real bass tone. This isn't the loudest bass amp in the world. Go find an old SVT if you need this tone but with loads more power. Better yet, find a rare Matchless Thunder Chief if you want a reliable SVT that will out live us all. Good luck finding and paying for one of those. Anyway, I just wanted a real studio bass rig to track with along side my UA 2-610 (which is an amazing bass DI!). I originally had my heart set on a B-15N. This is an excellent alternative. Price couldn't be better too! My rebuilt B-25 doesn't seem to be as distorted as everyone else is describing. I have to turn mine almost all the way up to get some semi-buzzy tones. My pickups are passive so maybe that has something to do with it. The fact that mine has been rebuilt probably cleaned it up as well. I love this bass tone. Very full and super deep. Tons of flexibility in tone with the front panel controls. Not a modern bass sound at all. Very 60's/70's which is what I love. Not sure if I can find a fault in the tone. Perfect for me. Mine is very, very quite in respect to noise and 60 cycle hum. In fact, the first nos phillips 7199 I put in was humming and distorting all over the place. Watch it with those expensive little bastards. Wow! $40 for an amazing sounding 60's Sunn cab paired with an Ampeg B-25. Can't beat it.

Well, it can crap the bed just like any other tube amp. If you have a schematic, a voltmeter, a soldering station, a credit card, and some brains...this amp can be fixed on the cheap! My voltages were anywhere from 20 to 70 volts higher than the ones posted on the test points of the schematic. No big deal. B+ of 573 volts in mine! Be careful.

Ampeg will e-mail you a schematic upon request. I found it on schematicheaven. Great site! Since I can tech my own gear and this amp is much older than I am, I have no opinion on Ampeg's service.

This bass rig is quite possibly the most perfect setup for my situation. I'm sure this would be a great amp to play small clubs with too. Amazing tone. I also own an old Acoustic 370 bass amp head. Very cool as well but I'm a tube amp guy. I've been on stage many many times with a real SVT and 8X10 cab too. I'd like to try this B-25 with a 4X10 ampeg cab. In my eyes and ears, this B-25 is like a little SVT. SVT tone at managable volumes, perfect for the studio.

Its a 60's model, thats as far as i know. It works great for claypool/geddy lee to big round rock, to the funkiest of funk. The two channels have a bright and normal input. i haven't really looked at the back part of the head so i couldn't tell you much. this thing can get loud. we annoyed the neighbors with a acoustic 360 style 15 inch speaker with the volume at 4. more than enough power for me.
everything you could want. bass,treble, volume, and a boost for highs and lows. simple, easy to use, and it sounds good.

It gets kinda distorted but i think it might need some service so that might change. it sounds good but it buzzes and there is some crackling noise. its old though, the guy i bought it from toured for 30 years with it.

as of now, i don't have a back up, but i would definitely gig with it.

never dealt with ampeg.

if i could find this again if it was stolen or unserviceable, i would buy another. the only thing i don't like is the noise, but its old, so if i get it serviced, it should be fine.

1969 2 Channel, two Power Tubes, Two Pre Amp and a rectifier tube. Very Basic with Volume, Tone and Bass and swithes for Low and High boost. Power jack in rear and output to run into another amp if you like, No effects loop but with this head who needs one. About 60 Watts or so it is rated but it will crank. Plenty of power for small to mid sized venues. If it is a larger venue I chain it to SVT. Great harmonic Distortion for a Jack Bruce, Allen Woody, Berry Oakley tone. Not a modern sound but a 60's Blues or rock sound. Simple to use and great sound it has to be a 10. As an earlier user said 3 controls and two switches give you all the versatility that you need.

It sounds like my SVT but with about a quarter of the power. The amp is very quiet I run it through a 67 Fender Shoman Cab with a 15 Jensen and if I chain it to my SVT I runs though the 15 and a 4-10 Ampeg Cabinet. When you crank the Amp you do get distotion but it is not the brutl no musical distortion and alot depends on your playing style. With a pick it can be very aggressive and using finger style it is a soft subtle sound. The amp is very quiet which suprised me. I use a variety of Basses, Fender P Bass and Jazz Bass a P Bass Lyte, Epiphone Jack Cassidy, Gibson EB-2, Gibson Thunderbird, Waterstone Hollowbody, Ibanez Jazz Lawsuit and a Gibson Ripper. The Humbuckers give the amp more of a growl.

NEVER gig wihout a backup. I have a B-100R as a backup in small clubs and the SVT is always with me at larger ones. I have never had a problem and it is a simple point to point wired amp that could be repaired with no trouble. The power Tubes are getting easier to find now Sovetek and Electro Harmonix are producing them for a while they were very hard to find but now you can get a matched pair for about $40

I have never had to deal with Ampeg. I suppose because they don't break so I can offer no opinion on Customer Support.

I have been playing 30 years and I have owned this amp for about 5 years. If it were lost or stolen I would find another one. I have a Ampeg B-100R as a backup, a nice transitor amp I must say, a SVT with a 4-10 Cabinet and the Basses that i listed above. If you find one buy it. It also makes a great Guitar amp and our Guitar player has used it to record. Ampeg is THE Bass amp and the B-25 is a steal compared to a vintage SVT.

it's a 1968 model, 55 watts, all tube. basically, a 1/4 size SVT. which makes it the PERFECT amp for me for small/medium shows, cause you can crank it and really get the tubes going, and it won't piss off the sound guy. it has VERY simple controls, two channels, each with a bright input, a normal input, a volume knob, bass knob, treble knob, and a switch for ultra hi, and a switch for ultra low. very simple. it has everythign you need, because no matter where you have it, it sounds great, and it's very intuitive. i use it with an ampeg 410 cabinet.

i use an american Fender Jazz bass('98 i think), standard setup, all passive. i play everything from dirty indie rock to chemical brothers-y electronica. this amp probably isn't the most versatile in the world, but i've never had a problem with it. if i want more bass, i turn up the bass knob and hit the ultra-low switch. more treble, i turn up the treble knob. i guess that's why i love it so much, everything just does exactly what it's supposed to. it starts to get that dizzly distortion at around half volume, but it's the GOOD kind of sizzle.

i've never had a problem.
to be quite honest, i don't know how it COULD break down, at least beyond reapir. it's all point to point wiring, and very simple setup. any problems with it i'd just fix. one thing that WILL happen is that because i'm using it to push a 410 cab, it's slightly underpowered, and the output transformer will eventually go. but i'm looking forward to that, because i'm just going to replace it with a larger transformer, and with very minimal rewiring it'll come out converted at about 160 watts!

never had to deal with them, the amp is 35 years old. but i'll give them a 10 because they're AMPEG. after all they've done for the world of bass, they deserve all the praise in the world.

i've been playing bass for about 6 years, i've played through many other bass amps, but the moment i found this and tried it, i fell head over heels in love. if it were stolen, i'd hunt down the thief, feed them their own arm and then piss on their ashes. if i lost it, i'd never forgive myself. if for some reason i needed a new amp, i'd get another one, or if i needed something bigger, i'd just get an SVT. CONCLUSION: if you need a gigging amp for small venues and you want SVT sound, this is the amp for you.

Its just a simple tube head with two channels volume, bass, treble. its only 50 watts but it screams! I'm using it to push a carvin cab with one fifteen and its loud enough to play just about anywhere.

I use a G&L climax bass with it and its a great combination. I play mostly new wave punk but I think you could use it with classic rock or metal. The amp distorts over half volume but the distortion sounds really cool.

I think its reliable but I havent had it long enough to make an informed judgement. Have a backup.

this amp is too old if you want customer support get something new.

Ive been playing bass for 6 years and I've had a couple of amps, Fender bassman, Carvin PB 150. this amp kicks the crap out of both of those. If it were stolen I'd get another if I could find one. I have had some trouble locating tubes for it but I don't really need them yet.