"hot rodding" a Blackface Bassman??

Joel66 · March 16th, 2005, 01:47 AM

Hi y'all. I was at the shop tonight where my Bassman is being recapped and was talking to the man doing the work. I told him that I've started lusting after a Marshall and a couple of Peavey amps. He told me "well after we get her back in top form we can hot rod her some".

What kind of things can be done to hot rod this amp, and what can I expect from them?

I love the Marshall overdrive sound from a JCM800 model 2204 I heard. I didn't hear it clean though. I also like the Peavey XXX, along with the Classic 50 half stack I tried. The Peavey's sounded good clean and dirty.

Then again, I love a good Fender clean sound. If I do hot rod the amp, will I lose my clean?

Thank you in advance,
Joel

fishman · March 16th, 2005, 09:40 AM

I've had mine modded some. I can't explain since im no tech. But you can add some gain to one side without hacking the amp up. I had the bass channel changed by tweaking the tone stack and making the deep switch a tone stack by-pass. I also put a master vol in the ext speaker jack that effects only the bass side. Plus the 2nd input on that side can act as a foot switch for the tone stack by pass.
The normal or "guitar" side is pure straight Blackface.
So it's a two channel foot switchable amp. Does it sound like a Marshall? NO. Never will. Does it have a great clean and a great drive tone yes. Look at Harmony Centrals reviews for Tim Swartz mods (a Swarty) He did mine.
You can go further but then you end up really altering the amp. Also a closed back cab with the right speakers makes a big difference. Im still working on that.

Ben Harmless · March 16th, 2005, 09:49 AM

I'll second that a hot-rodded Bassman won't sound exactly like a 2204. I know because I've got the 2204, and I've spent a whole lot of time listening to a hot-rodded Bassman.

If you want a good example. Listen to Social Distortion. While they use a number of different amps in the studio, the live tone is pretty much identical, and it comes from Bassmans and Marshalls. Whenever you hear one guitar playing, it's generally a goldtop LP with P90s through a Bassman.

That being said, the tones aren't so different that I can't cop a pretty good Social D with my 2204. You'll be able to be plenty happy with the Bassman. Truth be told, I'm in the market for a Bassman to complement my Marshall.

Great minds think alike, no?

halouis · March 16th, 2005, 10:49 AM

i've got one. I took a '68 bassman head i got for a steal, a JCM800 2204 schematic, and gave it to my tech to hot rod it. swapped EL34s in place of the 6L6s, modded the circuit to be more like a 2204 marshall JCM800. tons and tons of gain. no drilling ot chassis, but the knobs changed function to be a single channel amp. so hi+lo sensitivy inputs. a fat switch (ex-deep switch) treble, mid, bass, then preamp, MV, Presence.

its a screamer. and very Marshally. Originally it had too much brightness and not enough sweep in the gain. Took it back to the tech and we tweaked it. swapped in a new pot on the preamp knob.

THe tone is major Marshall territory, but with more bass than you could ever need. Nice to have. the low end is looser, more fendery than the trad. tight Marshall bottom end. I play it through a Marshall silver Jubilee 4x12 with V30s.

OTHERWISE, you may want to send to Billy Zoom who does all Mike Nesses amps. I almost had him do mine., but didn;t feel like llshipping to CA and back.

ANYHOW, feel free to click my web link and check out the MP3s on my bands web site. I did all the leads with the Bassman. Some rhythm too, but I can;t remember which. Most of the Rhythm was done with my real Marshall JMP 2204(same as JCM800).

Tim Swartz · March 16th, 2005, 10:50 AM

Here is a like to some Harmony Central reviews of Bassman head mods:

http://www.harmony-central.com/Guita...ad_Mod-01.html

fishman · March 16th, 2005, 10:54 AM

Hey there's MR Swartz now.
Do I get a referal fee???
I have the added advantage of living near him so I didn't have to ship

trag-o-caster · March 16th, 2005, 11:48 AM

I just thought that I'd chime in here, and sing the praises of Tim's work. If your within driving distance of him, then by all means he'd be the amp man to do business with. I'm about an hour away, and I've been taking ALL my amps to him lately. He knows amps inside and out, and he's a real gentleman to boot.

mr tom · March 17th, 2005, 02:04 AM

Yes, Mike Ness played through ONLY the BM when I saw SD in October; on the other side of the stage was a Marshall and...a BM head.

My own '66 has undergone Andy Ruhl's mods. I don't know if they're on line any more (Machine Gun amps), but they involve un-butchering the power amp and bias sections.

Oh, yes, I also took Mike K (KCA NOS Tubes)'s advice and rewired the Bass channel Deep switch to be a mid-boost. Highly recommended.

What a screamer this amp is! Marshally in the Bass channel, and like a hot blackface sans reverb in the Normal channel. Basically, it's the best of the earlier and later BM circuits, with a bit of creative tone-shaping involved.

The head currently, and for the foreseeable future, resides in a 2x10 Crusty combo (white Tolex, oxblood grillcloth, lovely and functional, etc.). It astounds everyone who plays through it - including me, and I play through it all the time. Currently it holds one Jensen P10R RI and one Reverend Alltone 30.

Hope this helps,

tom

Ben Harmless · March 17th, 2005, 04:04 PM

Quote:

Originally Posted by halouis

i've got one. I took a '68 bassman head i got for a steal, a JCM800 2204 schematic, and gave it to my tech to hot rod it. swapped EL34s in place of the 6L6s, modded the circuit to be more like a 2204 marshall JCM800.

That's really interesting. Did the stock power transformer provide the juice for the EL34s, or did you have to swap it out? I'd probably stick with the 6L6GCs just to have the contrasting tone, but that's an interesting thing to do.

It's my understanding that all Billy Zoom did to Mike Ness' Bassman(s) was to revioce the bass channel a bit, and generally clean things up some. All the rest is a BOSS SD-1 that Ness uses for leads. Some might argue that fact, (OD-1, OD-3, etc) but having recently seen him use one, and inspected it afterwards, I can attest to its truth.

Unfortunately, Mr. Zoom is not working on amps at the moment, though his web page has said that for quite awhile, and may not be up to date. Still, I think out own Mr. Swartz would be my first choice for help with my Bassman - you know, after I screw up doing the job on my own...

halouis · March 17th, 2005, 07:26 PM

I have thought about popping the 6L6s back in for a test. But I do have a nice 6L6 amp as well. my '68 Super Reverb which is killer on its own.

THe transformer is original. its big and hefty. no troubles.

yeah mine is a pretty major change. and like i said while its very Marshally, it's also got the fender thing happpening too. hybrid tone. Other bands who share bill with us always ask to play through it when I gig it.

Tremo · March 17th, 2005, 07:36 PM

Don't hack butcher that Fender.

If you want a Marshall sound, buy a Marshall, it's real simple.

Tim Swartz · March 18th, 2005, 01:11 AM

John, the reality is that to get a Marshall of the build quality of a Bassman would cost several times the price. Besides, a stock Bassman (talking the post presence control varieties), is pretty lackluster when stock. The mod I do is a great option for someone looking for boutique tone without the boutique price tag (and it is completely reversible).

March 16th, 2005, 01:47 AM	#1 (permalink)
Joel66 Tele-Holic Join Date: Mar 2003 Location: Cypress Inn, Tennessee Age: 41 Posts: 655	"hot rodding" a Blackface Bassman?? Hi y'all. I was at the shop tonight where my Bassman is being recapped and was talking to the man doing the work. I told him that I've started lusting after a Marshall and a couple of Peavey amps. He told me "well after we get her back in top form we can hot rod her some". What kind of things can be done to hot rod this amp, and what can I expect from them? I love the Marshall overdrive sound from a JCM800 model 2204 I heard. I didn't hear it clean though. I also like the Peavey XXX, along with the Classic 50 half stack I tried. The Peavey's sounded good clean and dirty. Then again, I love a good Fender clean sound. If I do hot rod the amp, will I lose my clean? Thank you in advance, Joel __________________ It takes a whole lot of liquor to like her but when I'm liquored up I like her just fine

March 16th, 2005, 09:40 AM	#2 (permalink)
fishman NEW MEMBER! Join Date: Apr 2004 Posts: 7	Bassman mods I've had mine modded some. I can't explain since im no tech. But you can add some gain to one side without hacking the amp up. I had the bass channel changed by tweaking the tone stack and making the deep switch a tone stack by-pass. I also put a master vol in the ext speaker jack that effects only the bass side. Plus the 2nd input on that side can act as a foot switch for the tone stack by pass. The normal or "guitar" side is pure straight Blackface. So it's a two channel foot switchable amp. Does it sound like a Marshall? NO. Never will. Does it have a great clean and a great drive tone yes. Look at Harmony Centrals reviews for Tim Swartz mods (a Swarty) He did mine. You can go further but then you end up really altering the amp. Also a closed back cab with the right speakers makes a big difference. Im still working on that.

March 16th, 2005, 09:49 AM	#3 (permalink)
Ben Harmless Friend of Leo's Join Date: Mar 2003 Location: Albany, NY US of A Posts: 3,244 6 Photos	I'll second that a hot-rodded Bassman won't sound exactly like a 2204. I know because I've got the 2204, and I've spent a whole lot of time listening to a hot-rodded Bassman. If you want a good example. Listen to Social Distortion. While they use a number of different amps in the studio, the live tone is pretty much identical, and it comes from Bassmans and Marshalls. Whenever you hear one guitar playing, it's generally a goldtop LP with P90s through a Bassman. That being said, the tones aren't so different that I can't cop a pretty good Social D with my 2204. You'll be able to be plenty happy with the Bassman. Truth be told, I'm in the market for a Bassman to complement my Marshall. Great minds think alike, no? __________________ "I think I'll go for the life of sin, followed by the last-minute, presto-change-o, deathbed repentance." - B. Simpson

March 16th, 2005, 10:50 AM	#5 (permalink)
Tim Swartz Tele-Afflicted Join Date: Mar 2003 Location: Michigan - Tweenst the Great Lakes Posts: 1,881	Here is a like to some Harmony Central reviews of Bassman head mods: http://www.harmony-central.com/Guita...ad_Mod-01.html __________________

March 16th, 2005, 11:48 AM	#7 (permalink)
trag-o-caster Friend of Leo's Join Date: Mar 2003 Location: Flushing, Michigan Posts: 4,558	Tim Swartz is DA MAN!!! I just thought that I'd chime in here, and sing the praises of Tim's work. If your within driving distance of him, then by all means he'd be the amp man to do business with. I'm about an hour away, and I've been taking ALL my amps to him lately. He knows amps inside and out, and he's a real gentleman to boot. __________________ Timothy Jon Lamb

March 16th, 2005, 10:49 AM	#4 (permalink)
halouis Tele-Afflicted Join Date: Mar 2003 Location: Virginia Posts: 1,404 7 Photos	i've got one. I took a '68 bassman head i got for a steal, a JCM800 2204 schematic, and gave it to my tech to hot rod it. swapped EL34s in place of the 6L6s, modded the circuit to be more like a 2204 marshall JCM800. tons and tons of gain. no drilling ot chassis, but the knobs changed function to be a single channel amp. so hi+lo sensitivy inputs. a fat switch (ex-deep switch) treble, mid, bass, then preamp, MV, Presence. its a screamer. and very Marshally. Originally it had too much brightness and not enough sweep in the gain. Took it back to the tech and we tweaked it. swapped in a new pot on the preamp knob. THe tone is major Marshall territory, but with more bass than you could ever need. Nice to have. the low end is looser, more fendery than the trad. tight Marshall bottom end. I play it through a Marshall silver Jubilee 4x12 with V30s. OTHERWISE, you may want to send to Billy Zoom who does all Mike Nesses amps. I almost had him do mine., but didn;t feel like llshipping to CA and back. ANYHOW, feel free to click my web link and check out the MP3s on my bands web site. I did all the leads with the Bassman. Some rhythm too, but I can;t remember which. Most of the Rhythm was done with my real Marshall JMP 2204(same as JCM800).

March 16th, 2005, 10:54 AM	#6 (permalink)
fishman NEW MEMBER! Join Date: Apr 2004 Posts: 7	Hey there's MR Swartz now. Do I get a referal fee??? I have the added advantage of living near him so I didn't have to ship

March 17th, 2005, 02:04 AM	#8 (permalink)
mr tom Tele-Meister Join Date: Mar 2003 Location: Michigan, USA Posts: 192	Bassman/Social D Yes, Mike Ness played through ONLY the BM when I saw SD in October; on the other side of the stage was a Marshall and...a BM head. My own '66 has undergone Andy Ruhl's mods. I don't know if they're on line any more (Machine Gun amps), but they involve un-butchering the power amp and bias sections. Oh, yes, I also took Mike K (KCA NOS Tubes)'s advice and rewired the Bass channel Deep switch to be a mid-boost. Highly recommended. What a screamer this amp is! Marshally in the Bass channel, and like a hot blackface sans reverb in the Normal channel. Basically, it's the best of the earlier and later BM circuits, with a bit of creative tone-shaping involved. The head currently, and for the foreseeable future, resides in a 2x10 Crusty combo (white Tolex, oxblood grillcloth, lovely and functional, etc.). It astounds everyone who plays through it - including me, and I play through it all the time. Currently it holds one Jensen P10R RI and one Reverend Alltone 30. Hope this helps, tom

March 17th, 2005, 07:26 PM	#10 (permalink)
halouis Tele-Afflicted Join Date: Mar 2003 Location: Virginia Posts: 1,404 7 Photos	I have thought about popping the 6L6s back in for a test. But I do have a nice 6L6 amp as well. my '68 Super Reverb which is killer on its own. THe transformer is original. its big and hefty. no troubles. yeah mine is a pretty major change. and like i said while its very Marshally, it's also got the fender thing happpening too. hybrid tone. Other bands who share bill with us always ask to play through it when I gig it.

March 17th, 2005, 07:36 PM	#11 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,736	Don't hack butcher that Fender. If you want a Marshall sound, buy a Marshall, it's real simple.

March 18th, 2005, 01:11 AM	#12 (permalink)
Tim Swartz Tele-Afflicted Join Date: Mar 2003 Location: Michigan - Tweenst the Great Lakes Posts: 1,881	John, the reality is that to get a Marshall of the build quality of a Bassman would cost several times the price. Besides, a stock Bassman (talking the post presence control varieties), is pretty lackluster when stock. The mod I do is a great option for someone looking for boutique tone without the boutique price tag (and it is completely reversible). __________________