Ampeg B25

Made by Ampeg

Posted By ActiveBass
Directory Equipment: Amplifiers
Rate/Review This Resource
Overall Rating: 4.5 (of 5)
Rating Votes %
1 50 ||
1 50 ||
0 0 ||
0 0 ||
0 0 ||
From 2 votes total

Member Reviews

On 5/18/2003, Chris Grimmoire (133) posted:
Overall Rating:
Owned many amps... Each one serves a purpose. This will give you a very fine overdrive at higher volumes...warm tone at any volume. High overdriven output, as tube amps tend to go. Great for RockinRollin. Makes any bassist sound like a badass.
Model Year: 1974
Price: $0.00
Where Obtained: lender amp
Very akin to the Fender Bassman 60. two channels, normal and bright inputs for each. Each channel has master volume, treble and bass.... with treble and bass boost toggle switches. Tube amp...
Sound Quality:
While seemingly limited compared to the Trace Elliots, SWRS, and Aguilar amps of our day...this lil head packs a lot of wallop, and a lot of pure tubeness, for a small powered (under 100watts) and light (under 40lbs) head. Strongly recommended for someone looking for a good overdriven bass tone at higher volumes without cracking windows...for someone who cannot justify selling off the firstborn for a decent Fender Bassman or Marshall Plexi.
Ease of Use:
The absolute easiest design out there... Plug into an input (choice of normal or "bright" treble boost) Dial up yer volume, bass eq and treble eq. Toggle a boost for each at your leisure. No graphic EQ, no compression, no lights, except on...standby switch in the is a TUBE amp.
Old Ampegs do not die. Replace tubes when you absolutely must...enjoy the interesting sounds til then...
On 2/8/2003, Jim Glen (10225) posted:
Overall Rating:
I've owned both Orange, and Marshall tube amps in the past, the Ampeg is in the same class, and pedigree. Better than a Marshall, and on a par, or Slightly Better construction wise, than Orange.

If I lost this amp or it was damaged beyond repair I would certainly look at trying to locate another.

This amp creates with ease that elusive 70's tube sound, and is tremendous to play through. The only potential drawback for an amp of this nature is that some of the tubes are now getting a little harder to find.
Price: $225.00
Where Obtained: Private Seller
This is an Ampeg classic 70's tube amp.

The Amp is all tube construction for both Pre and Power stages, utilising 2 - 12AX7's, and 1 - 7199 for the Pre-amp stages (these are the same Tubes currently used in Ampegs most modern tube amps, and tube pre-amps) The current rectifier uses a single 5AR4, and the Power section of the Amp uses 2 - 7027's.

When I was researching this amp prior to purchasing it I discovered that Ampeg had done some extremely clever engineering in the Power amp section. Although the Power stage currently uses 7027 tubes, the design is such that with a very simple easily performed modification the amp is capable of using almost ANY currenly available Power tube, including the readily available EL34.

The amp is rated for 8 Ohm cabinets, ouput is rated very conservativley rated 55w.

This 55w rating is however, very misleading, and the amp appears to have abundant power and headroom and easily generates high sound pressure levels.

The amp is mono, and has an output directly from the Pre-amp stage that can be routed to another power amplifier, or can be used for a Tuner.

As a result of the age of the amps "vintage" design, there is no effects loop available.
Sound Quality:
I plugged the amp into my Avatar BC412 playing my:
  • Rickenbacker 4003, and
  • Fender Jazz Fretless

  • Through the B-25,both instruments sounded wonderul.

    The B-25 was able to bring out the trademark Rickenbacker "Growl" very agressivley, and in addition, could also voice the wonderfull warm punch from my Jazz.

    Being an all Tube amp the sound is deep, rich and warm, when the tone controls are used effectively, the amp takes on a really strong aggresive sound, that still shines through as being produced from an all Tube amp.

    At low volumes the amp sounds surprisingly clean for its vintage, with very little tube noise. When pushed, delivers the trademark tube overdrive sound, still remaining clean and articulate.
    Ease of Use:
    The B-25 is as simple to use as any amp can be. On the front each of the two channels has:
  • Volume
  • Treble
  • Bass
  • Ultra High Switch
  • Ultra Low Switch
  • Power Switch
  • Ground Lift Switch
  • Durability:
    Given that this amp was made for only one year, it has survived approximatley 30+ years of playing and touring.

    I'm not at this time able to estimate how often the B-25 would need to be re-tubed, however this is directly related to how long and how hard the amp is played.

    The B-25 wieghs in at approximatley 45lbs, and is encased in a .75in thick wooden cabinet covered in black Tolex with armoured steel corners. The case is very well made, and the internal wiring appears to be done entirley by hand.