What are some good sounding small tube bass amp circuits?

[mort]

I know nothing about bass amps and I have someone inquiring about a small head/cab project for bass. Any idears?

And is there a such thing as a low powered SVT type circuit?

[J M Fahey]

Of course, what has been customarily used to record Bass for the last 50 years (or maybe 60? ): AMPEG B15 , they go from 30W cathode biased to 60W monsters a.k.a. fliptops

Better record one of these at the edge of clipping: fat, mean and punchy, than an SVT at low power.
A loud SVT at a studio is a Recording Engineer's nightmare.

[mort]

Of course, what has been customarily used to record Bass for the last 50 years (or maybe 60? ): AMPEG B15 , they go from 30W cathode biased to 60W monsters a.k.a. fliptops

Better record one of these at the edge of clipping: fat, mean and punchy, than an SVT at low power.
A loud SVT at a studio is a Recording Engineer's nightmare.

Someone else just gave me this same suggestion. I'm googling schematics but can you link me to a solid drawing of the b15 NF (1968??)

[mhuss]

Here's the B15-N...

[Enzo]

I think the B-15N sound oh so good.

[dchang0]

Trinity Amps makes a DIY amp kit for the B15 (you choose the variant you want to build), though I have not built one yet, so I can't render an opinion on it. A bassist friend may commission me to build one, I hope. Part of the problem is that genuine Ampeg B15s are fairly cheap, so building one doesn't make sense to him, so the request may never happen.

Trinity Amps - Vacuum Tube Amp Kits

If you happen to build one, please let us know how you like it, preferably with some audio clips and photos.

[überfuzz]

I often use a AB763 amplifier for studio recordings, sometimes live. If stock the AB763 preamp can pump a lot of bass. I recently designed a 130W-ish bass amplifier with two channels, a AB763 and a B-15N. The power stage + inverter is also a Fender rip off. If it sounds interesting I can post the schematics or maybe send it to you.

[Enzo]

The B15 electronics sound great, but also that Portaflex cabinet is a factor as well.

[mhuss]

The B15 electronics sound great, but also that Portaflex cabinet is a factor as well.

Does the new/current Ampeg 'flip top' 1x15 cab sound anything like the old ones?

[J M Fahey]

A tubed one, driving an Eminence Legend 15" (reasonably close to an old Jensen C15N) or even a modern "Italian"Jensen C15N ?
Certainly,why not?
M
Not NASA technology there.

Now the B15 something and even worse the Portaflex label has been attached to anything else Loud Technology wants to sell, wouldn't be surprised at Portaflex Condoms or Smartphones or whatever so has landed in VERY different and unrelated stuff.

Such as:


Portaflex PF500:

RMS power output: 500W @ 4 ohms
Preamp: MOSFET
Power amp: Class D

Portaflex 410HL

Handling 800 watts and featuring four 10″ Eminence® drivers and a selectable HF driver, the PF-410HLF is the perfect cab

Didn't find the Portaflex Condoms ad, hush hush is that it will be available after its presentation at NAAMM ... stay tuned

[Enzo]

I think this is the one to compare, not the PF model:


Ampeg: Heritage Series - B-15N




You may be right on the condoms Juan, after all I have my own brand...

[J M Fahey]

I think this is the one to compare, not the PF model:


Ampeg: Heritage Series - B-15N

[ATTACH=CONFIG]35828[/ATTACH]

^^^^^ Yup, that's the correct version.

Should sound like the original one, although I guess many will fall for the "new , improved" version

You may be right on the condoms Juan, after all I have my own brand...

[ATTACH=CONFIG]35827[/ATTACH]

Congratulations and hope you sell a lot

As of me, I won't be caught dead using them, imagine there is some slight problem with the "equipment" in use , the involved Lady reads instructions and finds: "In case of problems, roll your hand in a tight fist and hit it HARD with as strong a punch as you can"
Ouch !!!!!!!

Or the alternative: "plug it into a Variac and start rising voltage, hopefully reaching 120V "

[mhuss]

I think this is the one to compare, not the PF model:

I just want the cab, though, hence my wondering aloud...
Although it looks good from outside, I'll bet the innards are different.

[Enzo]

Well, that $3000 price tag might be a disincentive too.

Juan, I prefer to set my tremolo to maximum depth then advance the frequency.

[J M Fahey]

Naughty naughty boy