Played a Dumble bass amp

[Road Hat]

I got a call on Thursday asking if I was available for a session Friday at 4:30. I hadn’t played at this studio before, but I’d heard good things about it, so I got off work early and headed over.

I walk in, and the walls are awash with instruments. Over a dozen electric and acoustic guitars, all quality instruments (Fender, G&L, Gibson, Etc.). The owner points me to the ‘bass wall’ of amps and basses. Six different basses to choose from, Warwick, Fender, Yamaha, ovation graphite acoustic, all just killer. I’d brought along my trusty Fender Jazz/pbass hybrid, so I just needed amplification. He said to plug in anywhere. Okay, Hmmm, trace Elliot-nice, Ampeg-cool, Peavey-good stuff, hey-what’s this? Looks really familiar, but can’t be. Naw, no way, nope. What!!!

The distinctive lettering on the front said “Small Special 100”. I turned to the guy and said is this what I think it is? Yep, he says, that’s a 1972 Dumble I got new for $250 bucks from Dumble’s Santa Cruz shop. I told him I wanted a bass amp and this is what he built.

serial #...wait for it...wait for it...#014! 4x6L6, 12ax7s, looks like a Fender Bassman circuit to me. Huge output transformers, built like a tank, can’t believe it. He says set it up however you’d like. Two inputs, Volume, treble, bass, level. Four switches- Bright, Deep, Guitar/Mic, and Accent. Fired it up in Standby, and it had a sweet blue pilot light. Frankly, I didn’t know where to start, so I experimented a bit and ended up with Bright On, Deep Off, and Accent On (seemed to be a mid-boost). Volume at 3, Treble at 2.5, Bass at 2.5, Level at 3. It was plugged into a dual Showman cabinet with two 15” JBLs.

Earth-shaking.

I’ve never played anything like it. Notes didn’t pop, they exploded. The roundest cleanest sweetest tube tone imaginable. The amp played me, not the other way around. It’s like I was in competition with it to see if I could keep up with it. Dangerous Curves Ahead! Ha, you’re think you’re going to crank on the low E, just wait for what’s in store around that corner, kaboom! Hold on, wow, let’s try a chord, sonic boom!

I’m scheduled to go back in a few weeks, and I’ll see if I can get better pictures (sorry it’s so horrible). I didn’t have a chance to mess around with pictures and such, clock is ticking.

Best. Amp. Experience. Ever.

 

[bklee]

I got a call on Thursday asking if I was available for a session Friday at 4:30. I hadn’t played at this studio before, but I’d heard good things about it, so I got off work early and headed over.

I walk in, and the walls are awash with instruments. Over a dozen electric and acoustic guitars, all quality instruments (Fender, G&L, Gibson, Etc.). The owner points me to the ‘bass wall’ of amps and basses. Six different basses to choose from, Warwick, Fender, Yamaha, ovation graphite acoustic, all just killer. I’d brought along my trusty Fender Jazz/pbass hybrid, so I just needed amplification. He said to plug in anywhere. Okay, Hmmm, trace Elliot-nice, Ampeg-cool, Peavey-good stuff, hey-what’s this? Looks really familiar, but can’t be. Naw, no way, nope. What!!!

The distinctive lettering on the front said “Small Special 100”. I turned to the guy and said is this what I think it is? Yep, he says, that’s a 1972 Dumble I got new for $250 bucks from Dumble’s Santa Cruz shop. I told him I wanted a bass amp and this is what he built. serial #...wait for it...wait for it...#014! 4x6L6, 12ax7s, looks like a Fender Bassman circuit to me. Huge output transformers, built like a tank, can’t believe it. He says set it up however you’d like. Two inputs, Volume, treble, bass, level. Four switches- Bright, Deep, Guitar/Mic, and Accent. Fired it up in Standby, and it had a sweet blue pilot light. Frankly, I didn’t know where to start, so I experimented a bit and ended up with Bright On, Deep Off, and Accent On (seemed to be a mid-boost). Volume at 3, Treble at 2.5, Bass at 2.5, Level at 3. It was plugged into a dual Showman cabinet with two 15” JBLs.

Earth-shaking.

I’ve never played anything like it. Notes didn’t pop, they exploded. The roundest cleanest sweetest tube tone imaginable. The amp played me, not the other way around. It’s like I was in competition with it to see if I could keep up with it. Dangerous Curves Ahead! Ha, you’re think you’re going to crank on the low E, just wait for what’s in store around that corner, kaboom! Hold on, wow, let’s try a chord, sonic boom!

I’m scheduled to go back in a few weeks, and I’ll see if I can get better pictures (sorry it’s so horrible). I didn’t have a chance to mess around with pictures and such, clock is ticking.

Best. Amp. Experience. Ever.

View attachment 3165209

It's amazing how relatively simple circuits can yield great sounds. I have a semi-homemade amp with a similar layout (four 6L6s and 12ax7s with humongous transformers) that has the best sound of any amp I've ever played through. It lacks the switches and only has one channel, but I can dial in the sound I want from the knobs. I would use it on gigs if it had a direct out.

 

[petrus61]

That’s pretty awesome.

 

[JRA]

the only dumble i've ever played with was a drummer from new jersey.

but it sounds like a great experience, OP.

 

[b-b-b-bass]

Could you please take, and post, detailed photos of the inside circuitry, and also provide a verified schematic? Thanks !

 

[Hundred proof]

According to the prevailing TB mindset ... your actual "amp" experience is a figment of your imagination. Just plug in to a Sansamp direct it's all you need.

 

[chadds]

According to the prevailing TB mindset ... your actual "amp" experience is a figment of your imagination. Just plug in to a Sansamp direct it's all you need.

That’s hilarious and so true. Oh and forget the Showman with 15” JBLs. That’s so low rent. They didn’t know anything in those days because new is always improved. (Dripping sarcasm that’s too moist even for me!) Who needs tone when someone at the board can tell you what you sound like?

This lack of responsibility as musicians brought about disco. Play only covers long enough they figure, “I can pay one guy with the actual tunes.” We lost a decade of work. Reduce your signature and they pull up the Pbass with Seymour Duncans through SVT fridge patch and we’re done for again.

They won’t care that you can actually play and interpret a tune.

 

[Figjam]

ha comically terrible photo only adds to the allure.

That amp looks so cool. Damn.

theres a good chance he used peavey transformers for that amp. I believe lots of his early ones had em as they were beefy and cheap.

 

[LNM6753]

I got a call on Thursday asking if I was available for a session Friday at 4:30. I hadn’t played at this studio before, but I’d heard good things about it, so I got off work early and headed over.

I walk in, and the walls are awash with instruments. Over a dozen electric and acoustic guitars, all quality instruments (Fender, G&L, Gibson, Etc.). The owner points me to the ‘bass wall’ of amps and basses. Six different basses to choose from, Warwick, Fender, Yamaha, ovation graphite acoustic, all just killer. I’d brought along my trusty Fender Jazz/pbass hybrid, so I just needed amplification. He said to plug in anywhere. Okay, Hmmm, trace Elliot-nice, Ampeg-cool, Peavey-good stuff, hey-what’s this? Looks really familiar, but can’t be. Naw, no way, nope. What!!!

The distinctive lettering on the front said “Small Special 100”. I turned to the guy and said is this what I think it is? Yep, he says, that’s a 1972 Dumble I got new for $250 bucks from Dumble’s Santa Cruz shop. I told him I wanted a bass amp and this is what he built.

serial #...wait for it...wait for it...#014! 4x6L6, 12ax7s, looks like a Fender Bassman circuit to me. Huge output transformers, built like a tank, can’t believe it. He says set it up however you’d like. Two inputs, Volume, treble, bass, level. Four switches- Bright, Deep, Guitar/Mic, and Accent. Fired it up in Standby, and it had a sweet blue pilot light. Frankly, I didn’t know where to start, so I experimented a bit and ended up with Bright On, Deep Off, and Accent On (seemed to be a mid-boost). Volume at 3, Treble at 2.5, Bass at 2.5, Level at 3. It was plugged into a dual Showman cabinet with two 15” JBLs.

Earth-shaking.

I’ve never played anything like it. Notes didn’t pop, they exploded. The roundest cleanest sweetest tube tone imaginable. The amp played me, not the other way around. It’s like I was in competition with it to see if I could keep up with it. Dangerous Curves Ahead! Ha, you’re think you’re going to crank on the low E, just wait for what’s in store around that corner, kaboom! Hold on, wow, let’s try a chord, sonic boom!

I’m scheduled to go back in a few weeks, and I’ll see if I can get better pictures (sorry it’s so horrible). I didn’t have a chance to mess around with pictures and such, clock is ticking.

Best. Amp. Experience. Ever.

View attachment 3165209

What studio was this at?

 

[jlepre]

It certainly LOOKS to have SHAKEN a few things for sure.

 

[David Jayne]

Looks like you snapped the pic while playing a huge low E.

 

[rufus.K]

Did you go back?

 

[agedhorse]

According to the prevailing TB mindset ... your actual "amp" experience is a figment of your imagination. Just plug in to a Sansamp direct it's all you need.

I think you mis-characterize many (if not most) of the TB members with this statement.

 

[Hundred proof]

Call it what you want, there is certainly a mindset direct, direct, direct ... the sound person rules the roost it’s no longer about a sensible volume musical conversation on stage that is sent via “sound reinforcement” to the audience. It’s just easier and to use a fly rig to the house and trust in the result.

 

[BogeyBass]

Could you please take, and post, detailed photos of the inside circuitry, and also provide a verified schematic? Thanks !

lol... so they mystery can finally prevail !!

( Fender Copies) shhhh dont tell anybody

But yes it is rather amazing how such simple tone curves and a quad of 6L6 can work its magic. specially a 2x15 being powered by one.
i know the limits of the old shallow bassman cabinets. but at low volume they have a special tone in recordings. i also had some cheapo sealed Traynor 2x15s and loaded with some old turd eminence Gammas. dam do those things record well

Likewise how when ive worked with or recorded with very good musicians or session players.

they walk down the line and say nope nope nope ohhhh fender bassman. plug in nail the track in one or 2 takes

then the goobers that sit there and talk and talk and talk and really really picky about some amazing piece equipment they need.
usually freaking record all day long. take after take after take. then wanna annoy the krap outta me during mix down lol.
even then sometimes do dubs to fix the last track they did. or ill do them a favor a cut and paste the sections that are somewhat in time

 

[agedhorse]

Call it what you want, there is certainly a mindset direct, direct, direct ... the sound person rules the roost it’s no longer about a sensible volume musical conversation on stage that is sent via “sound reinforcement” to the audience. It’s just easier and to use a fly rig to the house and trust in the result.

I don't this is true either, I think the truth for the MAJORITY of players falls between the two extremes.

 

[agedhorse]

The basic Fender tone stack evolved as the instruments/pickups/speakers evolved, when pieces develop and evolve together, there's a synergy that works much of the time. The mid dip in the tone stack complimented the mid peak that was present in many of those speakers and cabinet designs back then.

That said, there are plenty of players who do not care for the Fender tonestack, either because of their instrument choice, the tone family that the music needs , their speaker choice, or simply personal preference.

 

[BogeyBass]

I kinda understand what Hundred Proof is saying. and got the joke

without specific details, the human need to argue on the internet lol. does play out strangely.

people will describe a real world experience, and somehow someone will make it sound like that didnt happen
or twist it up in some wierd way, for the sake of argument or wanting to be the one thats always right. comically discrediting a real event to be human.

not being comical of course, i say comical as in, i find it amusing. hence the snark and understanding i think 100 proof finds in human behavior

 

[Steve Dallman]

The circuitry is the same as a “standard” Dumble Overdrive Special, minus the overdrive. Dumble’s tone stack is a bit different than a Fender. Here’s a site with more pictures.

Invalid Link Removed

 

[b-b-b-bass]

lol... so they mystery can finally prevail !!

( Fender Copies) shhhh dont tell anybody

But yes it is rather amazing how such simple tone curves and a quad of 6L6 can work its magic. specially a 2x15 being powered by one.
i know the limits of the old shallow bassman cabinets. but at low volume they have a special tone in recordings. i also had some cheapo sealed Traynor 2x15s and loaded with some old turd eminence Gammas. dam do those things record well

Likewise how when ive worked with or recorded with very good musicians or session players.

they walk down the line and say nope nope nope ohhhh fender bassman. plug in nail the track in one or 2 takes

then the goobers that sit there and talk and talk and talk and really really picky about some amazing piece equipment they need.
usually freaking record all day long. take after take after take. then wanna annoy the krap outta me during mix down lol.
even then sometimes do dubs to fix the last track they did. or ill do them a favor a cut and paste the sections that are somewhat in time

I find my own experience to agree with most of your postings.

Here is my Pig-umble B100V modified bass head. It does record nicely.