68 custom vibrolux Mod to reduce Early Breakup

[Arbutt]

Just reduce the value of R45 (lower leg of the potential divider prior to the power amp, in place of the normal channel mix resistor) until he's happy.
The classic Fender value for R53 (power amp negative feedback resistor lower leg) would be 100R, maybe try that first.

Thanks PDF. I will look into the R45 swap and compare. and R53 change too

[Leo_Gnardo]

If what your customer ACTUALLY wants is for the amp to be as loud as it is at, say, 7 but still clean (which is what I suspect) then what he's asking for is more power. There's not much to be done for this. You could try more efficient speakers but this is harder to come by with 10".

^^^^^ This right here. Efficient speakers will make the most of the power you have available and can make QUITE the difference. More volume & in-your-face punch. One of my best customers has several Vibrolice AND Twins. JBL's in Twins, made-in-England Celestion G10's in the Vibros. For over 20 years now. He says "I don't understand how a Vibrolux can be LOUDER than a Twin??" In his experience the G10's bark noticeably louder than the JBLs, AND with half the power available. I'm taken aback as well, JBL's are pretty well top of the heap for efficiency. Though their tone isn't for everybody. Haven't made lab tests, I only have the subjective view from the player but I'm sure he's not misreporting what he experiences.

The current G10-like offering from Celestion adds Vintage to the title. And, made in China. Of course. Are they as good? I haven't compared so can't comment. Might be worth scaring up a pair of the good ol' Made In England G10's.

[loudthud]

Twin Reverbs are not very popular. If you can find one in a shop, you can probably talk them down quite a bit on the price.

[Chuck H]

The SPL for the current G10's is 97dB. Not bad, not great. That isn't to say they don't have something special in their respose curve that helps them punch and stand out. It's a popular speaker for the Vibrolux but reviews seem to be love 'em or hate 'em. YMMV. Eminence has a couple of 10's in the 100dB range but I can't report on their tone. I know I like their standard issue 1058. This speaker has been the jumping off point for a lot of good sounding proprietary 10's but Ive used them a few times and they do stand up just as Eminence makes them. I can't say that they're any louder than others though.

This said and if I interpret the thread correctly so far, I guess changing speakers is off the table anyhow.

[TomCarlos]

The SPL for the current G10's is 97dB. Not bad, not great. That isn't to say they don't have something special in their respose curve that helps them punch and stand out. It's a popular speaker for the Vibrolux but reviews seem to be love 'em or hate 'em. YMMV. Eminence has a couple of 10's in the 100dB range but I can't report on their tone. I know I like their standard issue 1058. This speaker has been the jumping off point for a lot of good sounding proprietary 10's but Ive used them a few times and they do stand up just as Eminence makes them. I can't say that they're any louder than others though.

This said and if I interpret the thread correctly so far, I guess changing speakers is off the table anyhow.

I have also used Eminence Legend speakers. Some time ago, a friend had a 4x12 cab and we compare a sngle 12 against three other speakers, including a Celestion G-75 (if remember correctly). The Legend 1258 held its own.

[glebert]

Hi all
I have a customer who has 68 custom vibrolux. He uses both channels,

Is he using both channels at once or switching between them?

Maybe this is misguided, but it sounds like he really wants a smaller Twin Reverb. Wondering if you were to try to change the Vibrolux to the 68 Custom Twin Reverb schematic as much as possible. Or tell him he bought the wrong amp, that always goes over well.

[g1]

Can anyone tell me how to delete a post?

Click 'edit' button (will only be possible within 24hrs. of posting). Click 'delete'. Confirm delete by clicking 'delete reply'.
Click on 'are you really really sure?' button. (j/k on that last one)

[Justin Thomas]

Thanks, found it!

[Chuck H]

The Legend 1258 held its own.

I tried the 1258 way back in 2009 for my own venture with DMS. It sounded fine, good even. But a little vanilla. It did get used in the proto cabinets but my own version of that amp is using V30's. That's just as tested with one particular amp though. And as we know speaker/amp pairings can be particular. Ergo all the available models. But some speakers get a good review almost universally and float to the top. One is the Mesa Black Shadow 10. And IMHO I think it may be very close to a stock Eminence 1058.

[Arbutt]

Thanks all for your help
Customer came and and we rebiased while he was here. seems to be happy with it now