Ampeg B-25

[trem]

I have one of these that has been gutted. Everything that's left is in good shape; trannies, chassis, face plates, etc. I have never really heard one of these amps, including this one that I own. I am wondering what to do with it. The two channels seem to be pretty similar except for a extra "Ultra Low" switch and V1b has its cathode by-passed. Maybe there is more....
So I was thinking to keep just one of the original channels and then do something else entirely with the other channel. If you guys were going to do what I propose, which of the two original channels would you keep?
Thank You

[tekhed7]

Chs 1 & 2 are pretty similar... Huh, trem? But if you concentrate on the "Ultra Lo" switching (the only real difference), only Ch 1 actually rolls off the lows... by reducing the effective interstage coupling capacitance.
So if I were you, I'd scrap [or "gut"] Ch 2 & rewire to be a nice, pre-CBS Fender design, w/ the standard tone stack. I never did care for the mid-shaping of the "HiFi" tone circuits Ampeg used anyhow. -tekhed

[AL30]

I own a B25. Personally I would put it back to stock. Yes, the channels are very similar BUT they are ridiculously versatile. The rocker switches do A LOT. You can get a Fender type sound out of it, you can get a very good low volume bass sound out of it. If you jumper the channels you get a FAT rock tone.

For the last several years (5-7?) I've played a 1964 Fender Bassman in a few different bands. I have gotten some nice compliments on my tone (always a nice thing huh?). I've played two shows with the Ampeg B25 and gotten more compliments than I did the entire time I was playing the Bassman.

They are unique sounding and versatile amps. As are all old Ampegs.

Now that I've said all that - here's my sales pitch. I LOVE that amp. If you don't want to take up the task of rebuilding it let me know. I would be interested in buying it off you. I've been toying with the idea of building one from scratch anyway. But I'd rather have the old iron.

I'm not here much but if you have any questions shoot me an email (I think my PM's go to my mail but I'm not sure). I may have some pics lying around - if not I can try and take some if it will help with the rebuild. And just for the record - I'm no expert or tech. I just love old Ampegs.


AL

[trem]

AL30
Thanks for your perspective. It would be nice to rebuild the stock circuits, which I planned to do originally. But it did not take long to realize the B-25 does not seem to be on the top of anybodies Ampeg list. So, I just started to figure that these amps were nothing special at best. Who knows, maybe they are a diamond in the rough that got overshadowed by Fender and Marshall. My amp will be all hand wired, so if I do not like the Ampeg content I can change it.
Thanks

[AL30]

Hi Trem,

Actually I think everything got overshadowed by Fender and Marshall.

The B25 is kind of a rarity also. It was only made for a few months in 1969. The B25B however was more popular and continued to be made. According to Ampeg book they are virtually the same amp with a different speaker cab. But the "B" was marketed towards bass players and the B25 was a guitar amp with no trem or reverb. Just a no frills workhorse.

I also think this may be under the radar due to when it was made. It just seems to be poor timing. It's got the early V-series cosmetics. That makes it compete with the SVT's, V4's and other power houses that the Stones were known to be playing. Who wanted a 50 watt, tube rectified bass/guitar amp when you could plug into a behemoth? But, if you look at the circuit it compares well to a lot of the older Ampegs and, with the exception of the 7199 PI it doesn't use all the wacky tubes found in the V-series.



Good luck with it. Have fun.

AL

[melvin]

I love the sound of that amp. It really seems that today it would be sought after. It has a great fat round as hell tone thanks to the rectifier and lots of bands are appreciating the low-wattage amps these days since live sound engineers don't really understand how to use a loud amp on stage.