using a guitar amp

[sqlb3rn]

I don't have a bass amp, but I have guitar amp and have been thinking about using it to join a band, until I can get a bass amp. The meat and potatoes is a Darkglass B7k Ultra v2, Peavey 6505+ amp head, and 412 cab with Celestion V30 speakers.

I tried running the b7k into the "return" fx loop and it seems to work and sound okay. The only way I can control the volume is with the Master knob on the b7k. I know I need to be careful not to blow the speakers with too much bass... but other than that, is there any reason why this won't work? It's essentially a 120w tube power amp into a 4x12 guitar cab.

 

[Stumbo]

I don't have a bass amp, but I have guitar amp and have been thinking about using it to join a band, until I can get a bass amp. The meat and potatoes is a Darkglass B7k Ultra v2, Peavey 6505+ amp head, and 412 cab with Celestion V30 speakers.

I tried running the b7k into the "return" fx loop and it seems to work and sound okay. The only way I can control the volume is with the Master knob on the b7k. I know I need to be careful not to blow the speakers with too much bass... but other than that, is there any reason why this won't work? It's essentially a 120w tube power amp into a 4x12 guitar cab.

You can but you need a High Pass Filter (HPF) to protect the speakers. Prolly set it around 100hz. You'll have mostly mids and with enough volume, can still blow the speakers. For more info see my Wiki: High Pass and Low Pass Filters | TalkBass.com

You might be able to pickup a bass cab pretty cheap these days, like a 4x10 that could handle the 120w head you have and it would sound okay for bass. Maybe add an external 10-band eq to get some good bass tone options in there. Put it up on a stand and still get the HPF.

FYI: I used a '60s Acoustic 150 with a matching 6x10 guitar cab for a rehearsal one time. No HPF. I cut the bass a lot, got enough volume to cut through. In the echo chamber of a high school lunch room that we were using, it was fine. The drummer was under control volume wise though. I would use it again and now that I have an HPF, it would be even better. YMMV.

 

[BassBeginer64]

Just that the Frequency range for those speakers are 70-5000Hz - most bass cabs are in the lower 40-50 Hz - missing out on a bunch of low end tone.
yeah HPF would not be a bad idea, till you can get a Bass Cab

 

[And I]

It's not voiced for bass. Aside from being at risk of ruining the speakers, it's not going to sound good. And it won't be loud enough to compete with a drummer and guitarists, which will increase the risk of blowing the speakers.

Can you borrow a bass amp? If not, can you run your bass through the dark glass pedal into the PA?

 

[sqlb3rn]

Thanks for the replies, I can probably at least get a cheap bass cab. I do have a MXR 10 band EQ and Maxon OD808 tube screamer which I think the tone knob acts as a high pass... but I will look for a cheap bass cab instead. Just so I have something to play through to join a band until I can get a real amp.

I could run the b7k DI, but I've never been in a band that had a decent PA so I can't count on it.

 

[musicman556]

Please do not destroy those sweet Vintage 30s. Check FB marketplace and Craigslist for some janky old bass amp for peanuts before risking that nice guitar cab. PUHLEASE! =D

 

[SteveIII]

There probably won't be much bass coming through. Amps voiced for high gain usually have small coupling capacitors and the output transformer won't pass much below 70 hz either. Now core saturation could cause problems. To play it safe get a bass cab.

 

[And I]

i'd go for a combo amp. the 6505 is not voiced for bass and will sound thin even if plugged into a bass speaker cab. it might work okay on the clean channel... maybe...

 

[Steve Dallman]

With only 1.2mm Xmax it wouldn’t take much to blow V30’s with bass.

 

[Wasnex]

I don't have a bass amp, but I have guitar amp and have been thinking about using it to join a band, until I can get a bass amp. The meat and potatoes is a Darkglass B7k Ultra v2, Peavey 6505+ amp head, and 412 cab with Celestion V30 speakers.

I tried running the b7k into the "return" fx loop and it seems to work and sound okay. The only way I can control the volume is with the Master knob on the b7k. I know I need to be careful not to blow the speakers with too much bass... but other than that, is there any reason why this won't work? It's essentially a 120w tube power amp into a 4x12 guitar cab.

IMHO the only real thing you need to worry about is blowing the speakers. A lot of music was made in the 60s with 412 guitar speakers, but you probably want a full stack as a minimum if you are going to crank a 100W tube head. It will sound seriously old school and don't expect a lot of low end.

Even better if you have a pair of full stacks, as I think you may be pushing your luck with just a single full stack and bass. Pretty sure it was common for bass players to blow speakers in the 60s.

FYI, the Vintage 30 is rated at 60W, so the 412 has a 240W power rating. But this is the thermal rating, and not the mechanical power handling. @Stumbo 's recommendation to use a HPF is a good idea. The 6505 should have some built in high pass filtering, but I doubt it is set high enough to protect the speakers.

 

[sqlb3rn]

There are a lot of used 410 bass cabs under $100 at guitar center so I might just get a Hartke or Kustom or something. I have two 412 v30 cabs and could run it as a full stack, but I only wanted to risk 1 cab in case something went wrong.

The amp head actually has a good amount of bass... I'm not going through the 6505 preamp, just going in thru the fx loop return, and using the power amp section. The cabs sound treble-y tho so I cut the highs a bit on the b7k. I just wasn't sure what the risks were besides farting out and destroying the speakers.

I just tried the OD808 tube screamer and it def cuts/neuters the bass. Almost sounds like a down tuned guitar with that b7k distortion. I'm playing a 5 string in B standard. In my last band, I was playing thru their Hartke 3500 bass head and some old beat up dusty PA floor wedge and it actually sounded way better than it looked.

 

[Bass_Frequency]

I don't have a bass amp, but I have guitar amp and have been thinking about using it to join a band, until I can get a bass amp. The meat and potatoes is a Darkglass B7k Ultra v2, Peavey 6505+ amp head, and 412 cab with Celestion V30 speakers.

I tried running the b7k into the "return" fx loop and it seems to work and sound okay. The only way I can control the volume is with the Master knob on the b7k. I know I need to be careful not to blow the speakers with too much bass... but other than that, is there any reason why this won't work? It's essentially a 120w tube power amp into a 4x12 guitar cab.

What you're working on there with that rig is the Lemmy from Motorhead sound.
Not allot of bottom end but mids and allot of crunch. Lemmy had good Marshall cabs.

 

[zubrycky]

Let me tell one thing: You can practice without an amp. I'm doing that since I started to play, a few decades ago and never looked back.

That said, if you want to join a band, get a bass amp (Or use the one available at the rehearsal studio).

 

[mbell75]

Guitar thru bass amp=great
Bass thru guitar amp=terrible

 

[chadface]

There are a lot of used 410 bass cabs under $100 at guitar center so I might just get a Hartke or Kustom or something. I have two 412 v30 cabs and could run it as a full stack, but I only wanted to risk 1 cab in case something went wrong.

The amp head actually has a good amount of bass... I'm not going through the 6505 preamp, just going in thru the fx loop return, and using the power amp section.

That's probably your best bet. If it still seems to be lacking you could try a different preamp like ampeg or a sansamp bass driver.

 

[Ric5]

I don't have a bass amp, but I have guitar amp and have been thinking about using it to join a band, until I can get a bass amp. The meat and potatoes is a Darkglass B7k Ultra v2, Peavey 6505+ amp head, and 412 cab with Celestion V30 speakers.

I tried running the b7k into the "return" fx loop and it seems to work and sound okay. The only way I can control the volume is with the Master knob on the b7k. I know I need to be careful not to blow the speakers with too much bass... but other than that, is there any reason why this won't work? It's essentially a 120w tube power amp into a 4x12 guitar cab.

4x12 cabs are great for bass … in fact better for bass than guitar

 

[Ric5]

Guitar thru bass amp=great
Bass thru guitar amp=terrible

The old Fender bassman amps were great for guitar

 

[Jared Houseman]

Just go direct and use a monitor.
If you really need your own cab on stage, go direct from the DG to FoH and an eq pedal cutting all the bass to your amp.
It's not going to sound good on stage but FoH will be decent

 

[Allan Allan]

Use the head as normal, use the cab as normal. Avoid octave and fuzz pedals. You'll be fine. Like... You'll be fine with this rig forever. Learn to use the tone controls and You. Will. Be. Fine.

You're not going to break anything unless you're playing at full volume with feedback and unnatural (pedal assisted) tones which would probably break the stuff if you were playing a guitar anyway.

 

[CRich0205]

I use a 45 watt Randall tube head for practice and some
Small shows with zero issues. Loud enough with an efficient cab to get me over a drummer. Drive channel can be dialed in pretty nicely and I almost always have to run the bass knob down because it’s too much. At 120 watts you’re over the v4b’s rated output and nobody says that isn’t a bass amp. With a 410 cab you can probably turn the amp up enough to get the power tubes to break up anyway and have a killer OD tone. Get a bass cab and rock on until you decide you need a bass head.