Vibrolux Reverb OT Taps and volume

[Skeeter_pdx]

I'm sure this is a simple question so I really appreciate anyone who takes the time to respond.

I built a Vibrolux Reverb AA964 clone and am trying to get it dialed in. I play in a band that plays LOUD...like reaaaaaally loud. When I'm playing by myself or with other groups the amp is plenty loud with the volume around 4 or 5. I'm trying to see if I can get a little more volume and headroom out of this amp. I've tried swapping tubes and made sure the bias, B+ and plate voltages are good. Asides from that I'm wondering if using a different tap on the OT would make a difference. The schematic didn't have impedance values for the speakers, and for some reason--can't remember why--I set it up with the 8 ohm tap with two 16 ohm Jensen C10Qs in parallel.

I'm sure this has been touched on in other threads but my question is would using the 4 ohm tap with two 8 ohm speakers instead of my current configuration give me much more volume to work with. And if so how would it affect the headroom?

[HotBluePlates]

... I built a Vibrolux Reverb AA964 clone ... I'm trying to see if I can get a little more volume and headroom out of this amp. ... I'm wondering if using a different tap on the OT would make a difference. ... I set it up with the 8 ohm tap with two 16 ohm Jensen C10Qs in parallel.

... would using the 4 ohm tap with two 8 ohm speakers ... give me much more volume to work with. ...

The Amp will see the exact same load, and deliver exactly the same power output.

You might then think, "Aha! I'll change the speaker loading, mismatch the speaker vs tap, and change the load on the tubes!". Here, whether you go up or down, the power output will likely decrease some.


You might be thinking of transistor amps, which deliver more output power as the user decreases the speaker-impedance (until the user goes too low & burns up the output transistors).  Tubes don't work like that, and deliver max power into a single "optimum load," and somewhat less power if the load impedance is raised or lowered.


Where you might obtain some loudness is in Speaker Sensitivity.

If you have something like a pair of Jensen speakers with 94dB/watt sensitivity and your new pair of speaker are much more sensitive (like 100dB/watt), then the new pair will be much louder with the same applied power.

[Latole]

General rule for more headroom:

1- More voltage.
2- Bigger filter caps.

[Merlin]

Impedance doesn't really affect volume, but the number of speaker cones does. If you can plug in twice as many speakers you'll get 3dB more volume...

[mresistor]

Impedance doesn't really affect volume, but the number of speaker cones does. If you can plug in twice as many speakers you'll get 3dB more volume...

Yes  consider the blackface Super Reverb  Tweed Bassman  or a Marshall half stack.

[Willabe]

Impedance doesn't really affect volume, but the number of speaker cones does. If you can plug in twice as many speakers you'll get 3dB more volume...

Hummmm, how much with this? 

[mresistor]

Where was Garcia and company playing? Somewhere in CA probably. 


https://www.reddit.com/r/OldSchoolCoolMusic/comments/eq24m1/the_famous_wall_of_sound_created_by_owsley/?rdt=59814

[shooter]

interesting aside;


those Crown amps that drove big venue speaker walls were "re-purposed" by the start up company, Technicare,  I worked for after the Navy.  they modified them into Pulsed DC amplifiers to drive the X-Y-Z gradient coils used to "pinpoint" a spot in 3D space to a specific magnetic "strength" for use in MRI scanners.


if you've ever had an MRI, the "jackhammer" sound are those gradient amps pulsing

[Willabe]

Where was Garcia and company playing? Somewhere in CA probably.

    Who cares.

They were goofy, all of them, and so was their music. Never listened to them. Yep, I said it. You can have em.

There was a 1000 bands and guitar players better than those goofs.

[bmccowan]

Agree that more efficient speakers and/or an extension cab is the way to go - or my favorite, tell your damn mates to turn it down a notch!
The Dead - I was never a big fan. But, I admired them for building a following by allowing audiences to tape their shows and produce bootlegs. I also am a fan of the music Jerry produced with Dawg Grisman.

[mresistor]

There's only a few dead songs i like.  so no biggie    I was trying to figure out what speakers the guy was using in the wall.

[Willabe]

I was trying to figure out what speakers the guy was using in the wall.

JBL's.

[shooter]

least they had good speakers, pink Floyd used bricks

[Willabe]

least they had good speakers, pink Floyd used bricks

JBL's suck.  Too bright, alum. dust cap and too clean.

Floyd used Fane speakers to my knowledge and they're great speakers. Their being remade and guys are flipping over them!

[shooter]

the wall.

pink Floyd used bricks

I see you went to public schools
 

[stratomaster]

Aggressive and efficient speakers will be your best bet.

I like the Eminence Ragin Cajun for cutting and moving more air than is reasonable for a 10".

[Willabe]

I worked as Johnny Winter's guitar/amp roadie 1 time, late 1980's? He flew in to play at the Blues fest in Grant Park, Chicago, with Muddy's old band that Johnny recorded with on 3 albums. The albums were on Johnny's label, Blue Sky Records and he played on and produced them both.

So he was renting back line amps, a BF SR and a BF TR. Johnny had me go down to play through the amps to make sure they were working fine and that they didn't have JBL's! He would not use them. He told me Jensen's, CTS, even Celestion's were ok, but NO JBL's!