ok, last thread about volume (much more technical)

[drew_half_empty]

yep, that's right, last thread, this is assuming that I get some good responses though

well, i looked on ebay, and bassman 100's are going for...well, nothing short of dirt cheap. I know this would only mean a 3db increase, however, I'm needing a totally clean amp, and the bassman 50 gets a good deal louder after the initial breakup.

So here's my thinking - if i can get one with a power section that stays clean BEYOND maxed volume, then i can put an EQ pedal in the effects loop & hopefully give it atleast a 5db boost

so, in short, is this possible? I realize it'd probably mean a massive output transformer, maybe adding another negative feedback loop, maybe something i'm missing - who knows, but can it be done?

 

[B2D]

Re: ok, last thread about volume (much more technical)

Keep in mind that dB's are a logarithmic meaure and not a linear one. 60 db is twice as loud as 50 db, for instance. a 10dB jump = twice as loud. so 3 db is a little more than you might think.

When you put a +5dB boost via pedal in the FX loop basically what you're doing is getting the power section to see more signal. Based on my experiences here a little goes a LONG way. Breakup of each amp is individual to the model and the tubes i's running but 100W of tube give you more headroom, for sure. I've never seen anyone fry their power section with an EQ pedal boosting volume so I'd say yeah you're safe with that.

Basically what you're asking for is a loud tube amp with no breakup whatsoever, and then a boost on top of that. The only amp I've had experience with that I KNOW will do this is a Fender Twin or Twin Reverb of the high-wattage type. I don't know how Bassmans react though.

Hope that helps... anyone else?

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

well my thinking is that with a new output transformer - a really efficient one designed to handle quite a bit more than 100 watts, will help a lot

I'm not sure how twins are able to stay clean like that but i'm sure it can't be that drastic of a circuit change

I should also add that it'd be nice if it was switchable between 4 & 8 ohms, right now with the 50 (4 ohms) I'm running an 8 ohm cab, which probably pulls down the headroom just a little, but it sounds better with that mismatch...but i dunno how it'd sound if it was 8 ohms instead of 4 so i'd like to have that option

 

[mrid]

Re: ok, last thread about volume (much more technical)

Just get one of those 135 watt Fender Twins with the ultra-linear trannys and be done with it! :laugh2:

Also, I don't quite know what to make of your persistent multiple NFB loop comments. You can play with resistor values to increase or decrease the amount of NFB in the existing circuitry.

 

[Artie]

Re: ok, last thread about volume (much more technical)

maybe adding another negative feedback loop, maybe something i'm missing - who knows, but can it be done?

"Adding" another NFB loop wil decrease power. Its negative, (out-of-phase), feedback. Besides, as mrid said, you don't want to add or subtract one, just play with the resistor values that are already there. And even then . . . you must know what you're doing, or you could end up with some serious oscillation.

 

[JeffB]

Re: ok, last thread about volume (much more technical)

You may want to try messing around with tube types as well. Go for some lower gain pre-amp tubes, and have it rebiased with something like 6550's in the power section which will help it have more headroom.

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

i already have pretty high headroom tubes

anyone else?

 

[Quencho092]

Re: ok, last thread about volume (much more technical)

after you get the bassman 100, buy a mercury magnetics Marshall Major output transformer. Trust me, this should really really boost your volume more, as marshall typically had excessively oversized OT's. The Marshall Major OT is designed for 200W+, so there should be no problem there IMO....You can also go multi-tap on the secondary for the transformer-wire the speaker out for 4 ohms, and the ext speaker for 2 or 8. this way you can run both of your cabs at full efficiency(2 ohms if both cabs are 4 ohms) (this is presuming they're all in parallel, hooked up to the same jack.)

Why didn't you go for a big ol twin in the first place is what i'm wondering. Any good twin will give you tons and tons of headroom, and tone to die for, especially for your style which i believe is some sort of hardcore/rockabilly. I'm really getting into the rockabilly style too and am looking to swap out my OT for headroom and bass response, so I've done my research if you need to know anything else.

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

yes, rockabilly owns

soon enough you'll say "i'd kill somebody if i got a ray butts echo sonic outta the deal"

and i just don't like the way twins are voiced, I'm seriously gonna start collecting bassmans cuz every one i've played sounds AMAZING.

and, well, about that OT, how will it affect the tone?

 

[rspst14]

Re: ok, last thread about volume (much more technical)

Keep in mind that dB's are a logarithmic meaure and not a linear one. 60 db is twice as loud as 50 db, for instance. a 10dB jump = twice as loud. so 3 db is a little more than you might think.

Not exactly...try ten times as loud for each increase of ten decibels...our ears perceive an increase of 10 decibels to be twice as loud, but the actual difference is 10x. I don't totally understand the physics behind why that's true, but it is. The ratio of quiet to threshold of pain is 1:10^12 (ten to the twelfth power.)

At any rate, I can't imagine that 50 watts wouldn't be loud enough. If you just need more clean headroom that's one thing, but otherwise 50 watts should really be plenty of power.

Ryan

 

[B2D]

Re: ok, last thread about volume (much more technical)

Not exactly...try ten times as loud for each increase of ten decibels...our ears perceive an increase of 10 decibels to be twice as loud, but the actual difference is 10x. I don't totally understand the physics behind why that's true, but it is. The ratio of quiet to threshold of pain is 1:10^12 (ten to the twelfth power.)

At any rate, I can't imagine that 50 watts wouldn't be loud enough. If you just need more clean headroom that's one thing, but otherwise 50 watts should really be plenty of power.

Ryan

Thank you for educating me.

...and alls I know is that my 50W Rectoverb will rattle windows on 4. I played it for a few hours with my friend's band with the volume on 7-8 without ear protection (my bad) and not only were we drowing out the hard-hitting drummer, my ears rung for 4 days after that.

 

[Edgecrusher]

Re: ok, last thread about volume (much more technical)

You know for all the changes your contemplating I cant imagine it would retain the exact same bassman tone... If your swapping in a Marshall Major tranny and adding 5db of boost its gonna change...Probably not a real economical solution either, they sure dont give those trannys away... If you like the bassman sound but need more of it... Why not just add another bassman too your rig and run two?

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

if eminence made 16 ohm legend 125's, i would, edge, really

 

[BornToShred]

Re: ok, last thread about volume (much more technical)

Keep in mind that dB's are a logarithmic meaure and not a linear one. 60 db is twice as loud as 50 db, for instance. a 10dB jump = twice as loud.?

Nope. 6dB = twice as loud.

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

no, that's not true

a 1,000 watt amp is twice as loud as a 100 watt amp

100 - 0
200 - 3db
400 - 6db
800 - 9db
1000 - 10db

but yeah, I'm thinking a 3-4 db change will be sufficient

 

[FretFire]

Re: ok, last thread about volume (much more technical)

I still want to see an SPL reading from one of your practices.

 

[B2D]

Re: ok, last thread about volume (much more technical)

I still want to see an SPL reading from one of your practices.

As would I.... I'm really curious about this.

 

[drew_half_empty]

Re: ok, last thread about volume (much more technical)

alright, fine, it'll be awhile, but after i get my new head, and my other 2x12, i'll get a meter

 

[muttonchopsrule]

Re: ok, last thread about volume (much more technical)

i still can't imagine needing anything more than 100 watts.

keep in mind that between a 50 watt and 100 watt amp, there may be just a 3 db increase, but the difference is in headroom. how high do you have your volume set now?

 

[FretFire]

Re: ok, last thread about volume (much more technical)

And how do you have your EQ set? Maybe you just need more MIDS to cut through, if you have the bass dimed and the mids dropped you're going to blend right in with the bass player.