• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Turning a guitar amp into a bass amp

jdwhitak

jdwhitak

Mar 20, 2012
407
79
Indianapolis, IN
#1
Hello,

I've been wanting a low wattage tube amp for my bass. I've looked around and there really don't seem to be any made anymore. I've been thinking about getting a tube guitar amp and converting it into a bass amp. Has anyone here done this? What amps make good canidates? What kind of mods would need to be done to it? Cost?

Thanks!
 
  • Like
Reactions: lowendrachel
#3
I would say 25 watts or less. I just play at home these days. I don't need something for a band.

Fender Bassman 100T? Sorry, I'm not looking to spend $1500! I was thinking more along the lines of the cheap 5-15 watt tube guitar amps that are out there these days.
 
#6
Generally speaking, you would want to re-voice all the gain staging (cathode bypass caps, coupling caps, interstage attenuation) and EQ to voice it properly for bass. I would probably add more filtering in the powersupply to keep the low end tight, and possibly beef up the OT for better low end frequency response. Shouldnt be that hard, especially with a lower power design.
 
  • Like
Reactions: downlowuponit
#7
JGR said:
Generally speaking, you would want to re-voice all the gain staging (cathode bypass caps, coupling caps, interstage attenuation) and EQ to voice it properly for bass. I would probably add more filtering in the powersupply to keep the low end tight, and possibly beef up the OT for better low end frequency response. Shouldnt be that hard, especially with a lower power design.
Click to expand...

+1

jdwhitak said:
I wouldn't need to have anything done to it to make it play better with bass?
Click to expand...

Once you get done with that, or done paying someone to do it you may be looking at "cheap" anymore. Depends on what you want.
 
#8
just get any old low power guitar head and plug it into a BASS cabinet. you are done. don't sweat the minutae, it does'nt really matter if you're just playing at home. a stock bf/sf fender bassman head can still be had for very cheap and is the perfect candidate for what you're looking for. just my 2 centavos
 
#10
pgk said:
just get any old low power guitar head and plug it into a BASS cabinet. you are done. don't sweat the minutae, it does'nt really matter if you're just playing at home. a stock bf/sf fender bassman head can still be had for very cheap and is the perfect candidate for what you're looking for. just my 2 centavos
Click to expand...

I've seen guys using Epiphone Valve Jr heads in the the "Micro Rigs of Doom" thread.
 
#12
jdwhitak said:
I would say 25 watts or less. I just play at home these days. I don't need something for a band.

Fender Bassman 100T? Sorry, I'm not looking to spend $1500! I was thinking more along the lines of the cheap 5-15 watt tube guitar amps that are out there these days.
Click to expand...

I get the feeling you're talking about playing bass thru a combo guitar amp.

If so, i recommend you dont do it because the speakers in a guitar amp are low-excursion design, and are not suited for the lowere frequencies of a bass instrument.

That said, a bass player buddy of mine has been playing his BG thru an old b/f Fender Twin (85 watt) for years without a hitch. But he plays it at very low volumes.
 
#13
In the sub 500 dollar range I would suggest.

Fender Bassman 20 ( combo amp) 18watts

Fender Musicmaster (combo amp) 12watts

Traynor Bassmate ( several versions) (combo amp) 25watts

Ampeg SB-12 (combo amp) 25 watts

Ashdown little bastard (head) 30watts

Ampeg b25 ( head) 55watts

Fender bassman 50 (head) 50watts

Fender bassman 100 (head)100watts

Traynor yba heads

And????
 
#14
fuzzy beard said:
In the sub 500 dollar range I would suggest.

Fender Bassman 20 ( combo amp) 18watts

Fender Musicmaster (combo amp) 12watts

Traynor Bassmate ( several versions) (combo amp) 25watts

Ampeg SB-12 (combo amp) 25 watts

Ashdown little bastard (head) 30watts

Ampeg b25 ( head) 55watts

Fender bassman 50 (head) 50watts

Fender bassman 100 (head)100watts

Traynor yba heads

And????
Click to expand...

I would add to this very good list the Ampeg Gemini II and reverb rocket amps. These are found as guitar combos but sound beautiful running the amp to a bass cab. One could just rebuild the amp section into a headcase. They're good guitar amps too, but I'd love to have a Gemini II built into a head.
 
#16
Along with some of the previously mentioned options, the old Fender Champs can work well for your purpose. The combo's speaker won't stand up to bass, but it's simple to add a 1/4 jack so that the amp's output can be sent either to the combo's speaker or to a more robust external cab. (I have a Champ sometimes used for bass that I rehoused in a home-built headcase, so it wasn't anchored to the combo's speaker.) The Champ, like a lot of guitar amps in this category, starts shedding low end higher than is ideal for bass. However, if you're using a small guitar head only as part of a home practice rig, that isn't so much of a problem.

For the purpose of home practice, I'm with pgk and fuzzy beard: you've got a lot of good options, especially if you focus on small tube amps that can feed a bass cab.
 

Latest posts

Top Bottom
Back