Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: John on June 29, 2011, 09:07:15 am

Title: Bass amp question
Post by: John on June 29, 2011, 09:07:15 am
Well, now that I've built one amp (even though I'm not done totally yet) naturally I want to build another one! I'd like to build a bass amp for my buddy, something in the 30 watt range... something that will sound nice and punchy without huge volumes. He's got a Crate 220 SS right now and naturally, in our living room it's hard to get any definition out of it.

So, my question is, what is a nice simple amp, no bells or whistles. He's got a Digitech modeler that he uses for that.

Thanks in advance,
John
Title: Re: Bass amp question
Post by: bluesbear on June 29, 2011, 09:18:31 am
I built my bass player a 5F6a head with 5881's, with slightly lowered voltages and voiced a little better for bass than the original. I'm guessing it's around 35 watts. It sounds great at a not too horrible volume, unlike the Traynor he used to use.
Dave
Title: Re: Bass amp question
Post by: John on June 29, 2011, 09:29:38 am
Thanks!

Almost forgot- any issues I should be aware of making it a combo? Only one I can think of offhand is the tubes picking up the speaker vibrations, but I like mouting them on top of the chassis anyway.

I think I read somewhere that a 10" speaker seems to be preferred for bass. Is that right or just some guy's opinion?

Thanks again,
John
Title: Re: Bass amp question
Post by: bluesbear on June 30, 2011, 07:18:48 am
If I was building a combo, I think I would try a Eminence Basslite Neo bass speaker, whatever size I decided on. They're supposed to have great response, both bass and high end. Also, they weigh far less than any non-neo bass speaker. I actually like 10" for bass but I like 4 of them. Maybe a 12" would be better for a lower power bass combo. I actually plan on turning the one I built into a combo with a 15". For now, he's using it through a 4 - 10" Traynor cabinet. It sounds great but it's big and heavy... and we're always saying, "I'm getting too old for this crap!"
Dave
Title: Re: Bass amp question
Post by: spacelabstudio on June 30, 2011, 08:58:37 am
If I was building a combo, I think I would try a Eminence Basslite Neo bass speaker, whatever size I decided on. They're supposed to have great response, both bass and high end. Also, they weigh far less than any non-neo bass speaker. I actually like 10" for bass but I like 4 of them. Maybe a 12" would be better for a lower power bass combo. I actually plan on turning the one I built into a combo with a 15". For now, he's using it through a 4 - 10" Traynor cabinet. It sounds great but it's big and heavy... and we're always saying, "I'm getting too old for this crap!"
Dave

I'm a big fan of a single 15", but it's all down to personal preference, really.  4 10"s have more total cone surface.  If you're only going to put out 30 watts from the amp you'll probably want the speaker system to be as efficient as possible, so more cone surface area might help.  Take a look at driver sensitivity on the spec sheets.  Neos are probably a good choice if you like the sound.

Chris
Title: Re: Bass amp question
Post by: John on June 30, 2011, 02:10:44 pm
Thanks for your replies. This is nothing I'm doing yesterday, and first I've gotta make sure he'd actually like a tube amp to play through.... he's more of a SS guy. I'm trying to convert him. Although I guess really with a bass amp it's not as  big of a  deal anyway?
Title: Re: Bass amp question
Post by: PRR on July 03, 2011, 08:31:10 pm
> really with a bass amp it's not as  big of a  deal anyway?

Indeed.

> in our living room it's hard to get any definition out of it.

Less-flubby speaker.

Stack mattresses in the corners.

Residential drywall is never good support for bass... garage? Basement?

Title: Re: Bass amp question
Post by: Willabe on July 03, 2011, 09:12:03 pm
> in our living room it's hard to get any definition out of it.
Stack mattresses in the corners.

Anti corner loading?

Residential drywall is never good support for bass... garage? Basement?

Low end gets absorbed by drywall, but higher frequencies get reflected by same?

End result...   no/bad bass definition?  

What was the acoustics soundproofing/physics author? F. Alton Everest. My friend has 4, 5 books by him. I had a book by him 20 years ago, built a few home studios that --- really ---worked unbelievably well as far as isolation/for the $$$ .


     Thanks,     Brad      :think1:

  
Title: Re: Bass amp question
Post by: supro66 on July 04, 2011, 08:25:34 am
A Supro 6420 is an easy build

2--12AX7 tubes
2--6L6 tubes

I got all of the plans
Title: Re: Bass amp question
Post by: 6G6 on July 04, 2011, 09:29:13 am
I think the Ampeg B15N is the definition of a low power, tube bass amp.