Uberschall rev. 2 users, help needed

BaRTY

BaRTY

New member
Hey, folks,
I got a nice rev. 2 uber from japan.
I noticed that it had minor mods here and there. I want to make it stock again.

Can somebody who owns rev. 2 send the deatiled pic of V4 area?
Here is mine:
https://photos.app.goo.gl/xyJRP7AmJQnThJs92

It seems like mine has some additional resistor (see that light brown resistor? down from v4).
 
One thing I can see is you have KT88 mod which allows you to run KT88's. I would leave that :)

So I circled the differences that I could see. The arrow points to what I have been told is the KT88 mod. Changing that 1 resistor allows for KT88.

The circle next to it I noticed yours are black and mine is silver.

The top left circle mine is red and yours is black and the bottom circle looks to me that the little teardrop looking thing is soldiered to the same place as the resistor on yours but is soldiered next to it on mine.

I have no idea what any of this means and my terms are probably wrong. I am sure that is not called a little teardrop thing but that is all I got for you :)


good image hosting site

Here is stock photo without all my fancy drawings for you. It’s worth noting, I bought my amp used. I believe it is stock but I cannot confirm.



good image hosting site
 
BaRTY, I'd be interested to know what serial sign/number is... I've got what I believe to be a very early rev 2 and here's what I can tell, based on maddnotez's pics (thanks for posting those!!).

1. Upper right circle (KT88 mod:) Mine is different than both. I have two blue resistors (I'd have to look up the value) like maddnotez, but underneath the one on the left, I also have a brown resistor wired in parallel. I'm not sure what this means, but I believe that it does affect the bias and would be changed for the KT88 mod. I can't read resistor values by sight, but I can look up the values (and resultant value of the parallel resistors).

2. Upper left circle: My cap is red, also like maddnotez.

3. Bottom circle: I also have the little teardrop thing (pretty sure that IS the technical term ;-) but I've heard it called a capacitor, too), but mine is wired on top of the resistor like BaRTY's. I think this is a cathode bypass, but it could be a plate bypass. I'd have to trace the circuit to be sure.

4. To the left of the left circle, directly in front of the closest red capacitor to the left of the circle, labelled on all as R121. I have 3 resistors stacked on top of each other. These look to be installed by the same hand that did the rest of the board, same amount of solder, same amount and color of resin, and I *think* they are original. Both BaRTY's and maddnotez's amps don't look like this is the case, as they both use a different value resistor than mine. Again, I can look those values up, but don't have them in front of me at the moment.

What I'm wondering is how these three amps line up chronologically. I think mine is from late 2001, based on the transformer dates.
 
Cool! Mine is dash dot slash (061). My PT is from Nov 2001.

Other than the differences maddnotez and I mentioned above, and a few labels that are in slightly different locations, I'm really not seeing a lot of differences here. I do have revision C of the EQ board, and yours is revision D, but I seriously doubt this was anything more than a solidification of parts values. Again, I haven't gone through the part values with a fine-tooth comb, and I'm far from an expert (I've only owned an Uber for about a month or so), but I am very interested in what parts of the circuit were still being tweaked.

What mods do you know or were told were done? I agree with maddnotez that, if you have the KT88 mod, you should keep it. It's always nice to have options.
 
The seller didn't mention any mods.
I can't even confirm that it has a kt88 mod. You just guessed it, right? )
The evidence is that it has a modified bias resistor, one mod on clean channel V4 (resistor and capacitor), some of the capacitors were changed.

I will try to change power tubes tomorrow. I don't have the probes, but I do have a bunch of 1Ohm resistors to make a bias test points. )
 
Just make sure you start on the low end of the bias current. :) If you haven't ever biased an amp before, it'd be worth it to take it somewhere and pay them to do it and teach you. It is easy, but there are very high voltages that will destroy your amp, seriously injure you, and/or literally kill you. Just be careful, ok?

Technically, maddnotez was the one who mentioned the KT88 mod. I think he's quite likely correct.

I think that the V4 mod (resistor & cap) aren't anything more than a wiring difference. All 3 of our amps have them, they're just positioned differently but are wired the same.

I think that the replaced caps could have been a supply issue at Bogner the week yours was made, or they could've been changed later due to some failure, or maybe the previous owner was just messing around. Who knows? It could be that Bogner changed that cap on purpose sometime in between mine and yours, simple as that. As long as it works and is giving you the sound you want/expect, it's good.

Again, just curious... what tubes are you going to put in?
 
Yep, the caps could go for whatever reason. )
The sound amp produce is fine. I got a 2xx serial number uber before, so I know how it sounds. )

Regarding the tube change, I've got a matched quad of Sovtek's KT88.
 
ChurchHill":3l8fzhga said:
4. To the left of the left circle, directly in front of the closest red capacitor to the left of the circle, labelled on all as R121. I have 3 resistors stacked on top of each other. These look to be installed by the same hand that did the rest of the board, same amount of solder, same amount and color of resin, and I *think* they are original. Both BaRTY's and maddnotez's amps don't look like this is the case, as they both use a different value resistor than mine. Again, I can look those values up, but don't have them in front of me at the moment.

What I'm wondering is how these three amps line up chronologically. I think mine is from late 2001, based on the transformer dates.
Click to expand...

This item #4 is interesting to me. It has been said not all Rev 2's are created equal. Yours probably sounds the best :) although I do love mine I have heard people says they have owned two and one was clearly better sounding.

Mine is #192
 
Looks to me like they just opened the bias range up to accept more than just straight up EL34/KT77 tubes. I did the same thing to mine, because it sounded crushing with EHX 6550s in it :D

I'd keep it as it is - honestly - as the ability to bias into several different types of bottles is a dope feature :thumbsup: :rock:

Of course, YMMV. Congratz on a killer amp!!!
 
maddnotez":38zj7pls said:
This item #4 is interesting to me. It has been said not all Rev 2's are created equal. Yours probably sounds the best :) although I do love mine I have heard people says they have owned two and one was clearly better sounding.

Mine is #192
Click to expand...
Sorry to hijack the thread and sorry it took me a few days to get to this. Things have been crazy at work. Anyway... from what I can tell from the pictures of the 3 resistors that are stacked on mine, the value of the bottom resistor is 100k. I think that's probably the original design value. Once the other two resistors are added, the value becomes 83k. From the pictures of yours and BaRTY's, the value of your single resistor is also 83k. I'm guessing that my board was already populated when they made the decision to change the value to 83k and thought it was better the add the parallel resistance than it would've been to remove the 100k and replace it with the 83k. Resistors are cheap, good PCBs aren't, and I think they thought the risk of damaging the PCB wasn't worth it. Just my guess, though.

As far as the affect on the sound, I doubt there's much, if any, at least when not using the FX loop or line out. These resistors are on the same board as the loop, line out, and bias. Without looking at this further (I'm just looking at pictures, haven't pulled my chassis), I'm not sure exactly what this resistor does.

Back to the OP... Ventura's right. Having the ability to use multiple tube types is always a good thing! Let us know what you think of those new tubes!!

:rock:
 
Ventura":3142l21d said:
Looks to me like they just opened the bias range up to accept more than just straight up EL34/KT77 tubes. I did the same thing to mine, because it sounded crushing with EHX 6550s in it :D

I'd keep it as it is - honestly - as the ability to bias into several different types of bottles is a dope feature :thumbsup: :rock:

Of course, YMMV. Congratz on a killer amp!!!
Click to expand...
https://photos.app.goo.gl/QoTZWFMD7wbFlopn1
thanks
 
ChurchHill":v2rgy30v said:
maddnotez":v2rgy30v said:
This item #4 is interesting to me. It has been said not all Rev 2's are created equal. Yours probably sounds the best :) although I do love mine I have heard people says they have owned two and one was clearly better sounding.

Mine is #192
Click to expand...
Sorry to hijack the thread and sorry it took me a few days to get to this. Things have been crazy at work. Anyway... from what I can tell from the pictures of the 3 resistors that are stacked on mine, the value of the bottom resistor is 100k. I think that's probably the original design value. Once the other two resistors are added, the value becomes 83k. From the pictures of yours and BaRTY's, the value of your single resistor is also 83k. I'm guessing that my board was already populated when they made the decision to change the value to 83k and thought it was better the add the parallel resistance than it would've been to remove the 100k and replace it with the 83k. Resistors are cheap, good PCBs aren't, and I think they thought the risk of damaging the PCB wasn't worth it. Just my guess, though.

As far as the affect on the sound, I doubt there's much, if any, at least when not using the FX loop or line out. These resistors are on the same board as the loop, line out, and bias. Without looking at this further (I'm just looking at pictures, haven't pulled my chassis), I'm not sure exactly what this resistor does.

Back to the OP... Ventura's right. Having the ability to use multiple tube types is always a good thing! Let us know what you think of those new tubes!!

:rock:
Click to expand...
I couldn't find some resistors to measure tube bias. I will make a swap next saturday. Never tried uber with kt88s.
 
I think you'll like the KT88s. Just make sure you set the bias, though.

I've never tried an Uber with KT88s, but I really like them in other amps. KT88s are one of the reasons why I want a Twin Jet at some point, and one of the reasons I love my 20th Shiva (amazing amp). Have you used them before?
 
I had TwinJet once. Actually loved the 1st channel (juicy, hot rodded marshall sound), but 2nd channel was disappointing for me. It sounds different from rev. 2.
 
I've often wondered about that... I love what I've heard out of the TJ's ch 1, but ch 2 just didn't seem the same as either Rev 2 or Rev Blue. I lucked into the Rev 2 I have, but I've thought that the Rev 2 sounds more aggressive or maybe just less polished than Rev Blue. I could be wrong about all that, since I've only owned the Rev 2, but to be sure, they are all incredible amps.
 
I've tried EL34, KT77, E34L, KT88 and 6550s.

E34L was insanely good at lower volumes but got too bottom-end thick when the volume started moving furniture.
EL34/KT77, nice and juicy.
KT88s, bit glassy but that worked okay as the amp is a touch dark by nature
6550s kicked ass. And they're the EHX ones too - my local tech (famous cat in Vancouver named "Ho" from Ho's Electronics) recommended I go with EHX due to their build quality and plate-power capacity. Couldn't be happier with that choice.

To each their own, and to each amp, its own. The Rev's have variations within their lineage - part of the allure I suppose.

(for the record, I sold my mint Rev.2 to a very cool cat from WA....he's loving it!! I may get another one day, I am sure I will, but for now, the tones are getting totally satisfied with the Purple TJ and Slax for the brootz.)
 
Good to know about the E34Ls. I've had some amps that loved them and some that didn't so much. I was thinking about giving them a shot in my Uber at some point, but I can definitely see that the bottom might get out of hand.

Dropping some KT77s in mine soon. I've got a couple of cabs that need new speakers and a guitar that's getting a new bridge and re-wired, too. So, sometime soon.

6550s intrigue me, although I'm not sure that I want to modify mine if it can't support them now (which I doubt, but haven't checked).

Been hearing a lot of good things about EHX tubes, lately, especially in the Friedman forum. I've had good luck with their EL34s, 6V6s, and 12AX7s, but haven't gotten any for some time. Next time I need power tubes, if I don't go NOS, pretty sure they'll be EHX.

That Slax still doing it for you, huh? Sounds like a great amp! Still trying to figure out if I want to jump in with that, a JJ, or the new BE-50... and then rumors of a new Helios. Thinking '18's going to be rather amp heavy on my end. Not complaining, either... LOL!
 
ChurchHill":35l8jvcs said:
That Slax still doing it for you, huh? Sounds like a great amp! Still trying to figure out if I want to jump in with that, a JJ, or the new BE-50... and then rumors of a new Helios. Thinking '18's going to be rather amp heavy on my end. Not complaining, either... LOL!
Click to expand...
Ya, the Butterslax is actually giving me a lot of range and chunk and grit and brootz. It's a different amp. My JJ took seconds to dial in and with that, I played all night... The Slax has taken some time to fiddle with - the EQ is quite interactive on it, it's cab sensitive, guitar sensitive, and offers tremendous range. It's amazing. And different. I'd not know which one to part with between the JJ and Slax, I'd not want to make that choice... No way. Cuz I really love the JJ.

But as this is the BOGNER forum, the TJ to me is still the most consistent beast out of the bunch. That's not to say the Rev.2s don't rival it - WHEN you get a good one!! But I've had several Rev.2s, ALWAYS get excited with them, usually do a good job tuning them with proper glass, and then?? Well.... What happens "then" is that it slays like nobody's business within a certain style of music and tone - it reigns supreme. But it doesn't do much outside of this zone. That's a lot of coin for "specific tone" - but again - to each their own. I sold my last Rev.2 and kept my Purple Modded TJ - imagine that.... :dunno:

Anyway - they're interesting beasts. Love Ubers.... Love Bogners!! Excited to learn more about this new Helios I'm reading about above. Should be neat!!

Peace :rock: :rock: :rock: :rock: :rock:
 
Yeah, I'm really curious about this new Helios. It's already on my buy list, and even if the only change is foot-switchable gain levels, it's going to move up on that list. The Purple TJ is on that list, too, and I'm still loving my 20th Shiva. I've got a 101B, too, that is such a perfect amp. There's just something about all of them that gets so close to the tones in my head. Of course, I have other amps, too, and some of those are truly great (vintage Fender, vintage Marshall, Diezel, several others), but, well, there's just some magic in these Bogners.

I'm not generally opposed to specific tone amps, even if they're $$$, but only if it's a really really really good tone. Those kinds of things wouldn't necessarily be my first choice for gigging, but... well, sometimes, one just needs the right tool for the job.
 
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