SRV Vibroverb real deal not reissue...tonequest report amp..

[Roe]

SRV used jbl e130s, not D130Fs

[Structo]

Well after a gig last night I just hope SR (1965) still working. Took a fall rolling amp out to truck. (Black)Face first, has padded cover. No glass rattle so hope for the best. Dang it!!! To much in a rush. Lesson learned the hard way. I will give a look see exam later today. Crap!!!!

Man, hope your amp is OK.

I hate when a tube amp is dropped or worse.

I used to use a hand truck sort of device to transport my amp and speaker cabs.
I would lower down to a cart type config.
I had pneumatic tires that cushioned the ride.

I would love to own road cases for everything but the current budget won't allow for it......

[sepulchre]

I'm thinking one of the reasons it sounds awesome is that with an 8 ohm load, the amp produces 1/4 the output power compared to what the amp produces with a two ohm load. So it will go into power stage overdrive more quickly with the 8 ohm load.

Is there any risk doing this? I'm curious because it might what I'm looking for to use in small rooms (cramped bars, etc), not to mention at home.

[sepulchre]

I was jamming in the basement of a VFW a few years ago - sort of an open mic deal where anybody could join in. There was this older fella there who had a Beautiful old tweed Bassman that sounded great clean (I wondered how it would sound cranked). Well, when he packed up to leave another guy offered to help the gentleman out by hauling his amp up the rather steep stairs. He got almost to the top of the stairs and that old leather handle broke. I watched in horror as that gem tumbled and bounced down those concrete steps. It only hit on the sides, top or bottom, not on the face or back but it still was terrible to see. The owner just sat looking at it for a few minutes. Then he hooked it up, plugged in and strummed a few chords. It sounded as fine as ever. I didn't see it up close but it didn't even look like it had any very noticeable marks, amazing for the fall it took.

[roadkingbluzs]

All is well with the SR . Power light did not come on at first , readjustment and then there was light. As for the Vibroverb thing ,I may add a new baffle to an empty '68 SR cab to house a 15". Sad about that guys Bassman ,but I believe Fender built quality road equipment . Don't think they tested being thrown down a flight of stairs.

[sck1001931]

i made an edit to the topic. try changing the two input resistors from 68k to 100k too. this was one of cesar diaz mods that makes the amp sound more controlled. the sound doesnt get as over saturated and flubbed at higher volumes. it lowers the input signal sent to the tubes a bit and you really hear how it helps get you the SRV tone if thats what youre going for. easy and reversible mod that sounds especially good if youre playing chords like with "pride and joy" or "Im Cryin"

[Roe]

i made an edit to the topic. try changing the two input resistors from 68k to 100k too. this was one of cesar diaz mods that makes the amp sound more controlled. the sound doesnt get as over saturated and flubbed at higher volumes. it lowers the input signal sent to the tubes a bit and you really hear how it helps get you the SRV tone if thats what youre going for. easy and reversible mod that sounds especially good if youre playing chords like with "pride and joy" or "Im Cryin"

Diaz clearly misunderstood how these resistors work (remove highend)

[sck1001931]

===

[Reeltarded]

Diaz wasn't a genius, he was a huckster.

[martin manning]

going from 68k to 100k just lowers the input signal a bit before going to the preamp.

I don't know what Diaz was thinking, but this is not correct.

[sck1001931]

that what I read in a interview with him "68k to 100k to lower input signal to keep the tone more controlled at high volumes." if that's not correct then what is "correct"
just saying that's not correct doesn't say much. whether is correct or not it does make a noticeable difference in feel and tone. the 68k to 100k input resistor mod is even on the 64 vibroverb custom schematic diaz mod amp so I know he definitely did it. look up the schematic and see for yourself.

[sck1001931]

I can build amps and do all maintenance and mods but I didn't go to engineering school or anything. if you think an explanation is wrong, elaborate. I just go off stuff Ive read & learned from others like a lot of people in amp garage

[M Fowler]

Not sure what he is doing but I for impedance I like to use 1M on 1st input jack for strats/tele and 150k on input 2 jack for LP/humbuckers. Some have put a switch in for this purpose. My grid leak is usually 33k - 68k.

[martin manning]

The input resistors don't carry any current to speak of (the grid impedance is very high), so the signal voltage at the grid doesn't drop. As Roe alluded to above, they interact with the tube's input capacitance multiplied by gain (Miller effect), creating a low-pass filter. Using two 68k and the high input, there is 34k of series resistance (68k//68k). Combined with about 100pF Miller capacitance that puts the corner frequency at ~47kHz. Using two 100k brings it down to ~32kHz, so there is a slight reduction in the extreme high end and less RF noise coming through.

[sck1001931]

ok. cool martin. that makes sense and it sounds like you know what you're talking about. in any case, that reduction of the high end a bit does sound great playing chords at high volumes. but i still like the tone of the 68k input resistors for the individual notes