Check out Weber Attenuators. https://taweber.powweb.co.weber/minimass.htm Their speakers are great. I'm guessing their attenuators are good too. While there, why not look at the 8" Blue Pup for the Bugera combo

 
Thanks for the Weber link!
Think I'll pickup one of their attenuators...   

2) each pair of tubes sounded remarkably different... wit the ones drawing the most current sounding the most distorted. Please recall that these tubes were from a NOS batch of JAN Phillips tubes. They were all more or less supposed to sound exactly alike. The point being... it's likely that a better set of tubes will sound better... and to make best use of tubes you should check and adjust the bias of the power output tubes if needed.

 
Hi Mike,
 
Perhaps it's my limited (guitar) perspective... but that sounds a bit tedious. 
Reminds me of trying to set intonation on a Ric 4003... where you have to actually pull out the tail-piece to make adjustments.

Please... get a great Weber speaker BEFORE getting an attenuator.

 
Hi Mike,
 
Thanks for the help/information!
 
I like the Rebel 1x12 cab. 
It sounds a better to me (tighter with more detail) than the included speakers in the Tweaker combo, V22, and the 10" speaker in the Class 5.  The V22 and Class 5 both sounded better (to my ears) playing thru the Rebel's 80w Celestion.
 
That may be due to:
-V22 and Class 5 being brand new (speakers not broken in)
-Class 5's 10 (as opposed to a 12)
-The Rebel's cab is sealed... whereas all the combo's had open backs.
 
I will try some other "small" cabs (1x12) including a Weber.
My space is starting to get a bit 'cluttered' with guitar amps/cabs/etc.  
I went thru the same process with bass. 
Bought/sold a lot of different basses/amps/cabs deciding which I prefered.
Ultimately, I ended up liking the classics (Fender, MusicMan, and Ampeg).
With guitars, I lean the same way (Fender, Gibson, MusicMan).
The new generation of guitar amps are intriguing due to their reduced size/power/cost.
Out of the three little amps (Tweaker, V22, Class 5) my opinion changes almost on a daily basis as to which I like best.
 
How difficult is it for a novice (never swapped a tube) to change out tubes?
If it's not too difficult/tedious/dangerous, I'll probably give it a shot.  
Thanks for any advice/etc!
 
 

Jim Roseberry

2) each pair of tubes sounded remarkably different... wit the ones drawing the most current sounding the most distorted. Please recall that these tubes were from a NOS batch of JAN Phillips tubes. They were all more or less supposed to sound exactly alike. The point being... it's likely that a better set of tubes will sound better... and to make best use of tubes you should check and adjust the bias of the power output tubes if needed.

 
Hi Mike,
 
Perhaps it's my limited (guitar) perspective... but that sounds a bit tedious. 
Reminds me of trying to set intonation on a Ric 4003... where you have to actually pull out the tail-piece to make adjustments.

Yeah, but do it once...and you won't have to mess with it again. I would like to say, not all JAN's have the same character...the green label units that are most available are from the late '70s-mid 80's are very shrill and brittle sounding. The JAN tubes from the early to mid 60's are the ones to get. Most are white label, but some are green (I happen to have about 2 dozen green label 12AT7's from '64...so I know they are out there!)

Jim,
 Pre amp tubes are easily swapped.... for one primary reason: You do not have to worry about excess CURRENT melting the tube. Preamp tubes provide gain. In other words, they amplify VOLTAGE. If the resistor and capacitor on the cathode of a preamp tube are in the neighborhood of being sized correctly... you are fairly safe if you want to swap out and listen to differences. You can also re bias a cathode biased preamp tube if you have an opinion about what sort of gain and tonal response you want from your circuit. Very few people speak about this because the idea that cathode biasing is "self biasing" eclipses the recognition that at some point some designer biased the original preamp tube by wiring up the socket and it can be modded to taste.

That said, mixing a matching preamp tubes can be loads of fun... and as easy as swapping tubes after you let them cool to the touch.

Power tubes can also be swapped... but because they amplify CURRENT you have to worry about a maladjustment melting your tubes into cherry red lava.

Really. I'm not exaggerating.

Some manufacturers specify a range of suitable cathode current that relates to a tonal range on a particular amp and then grade their tubes using testers that allow them to predict how much current they will draw in your amp.

You can select clean sounding tubes or hot sounding tubes. Last week that is essentially what I was doing... although my tube vendor does not predict current draw in any particular amp. His tubes are graded along the range of current draw he sees in his test gear... and that correlates with what you will experience in your amp.

Groove Tubes was a well known company that graded tubes with the intention of making bias adjustment unnecessary. You were expected to get your amp adjusted the first time you selected a grade of tube and then you could predict the current draw of the same or other grades.

Meas Boogies does that now a days... your amp is preset at the factory and their graded tubes represent a range of clean to crunch.

For most tube amps it is expected that every time you swap a set of power tubes that you measure the cathode current and bias voltage and make an adjustment if necessary. Adjustments can be simple like adjusting a potentiometer or soldering in a new resistor value.

The time consuming task is measuring and calculating the cathode current.

In recent years there have been many bias meters introduced to the market that makes it quicker and easier. The CompuBias meter I use is one of those type of meters.

BTW, I generally agree with Ron that the old 1960's tubes are the best but I rarely see sets of them for sale in any circumstance I consider affordable or legitimate.

There are certainly great opportunities for one offs found here, there and everywhere. Which is one reason I like Champ style single ended single power tube amps. They only need one power tube.

BTW, the 12AT7 is a current driving tube with different impedance's than a optimized for voltage gain tube... In recent years DIY modders have been using it as a lower voltage gain sub for a 12AX7... which I don't get... because one can easily swap out the resistor on the 12AX7 to lower the gain to match a 12AT7.

I'm like Ron, I hoard 12AT7s. I do it because there are very few good new ones for use as a current driver or phase splitter.

Anyways... TMI, I'm sure.

all the best,
mike

Fender......distortion???!



burn him!!!

Hi Jim,

I started writing a boring and long post about the various distortion pedals.... I erased it and here are too good links instead. My post was reminding me of something a parrot with a bad memory might write... these links are closer to what I remember reading thru the years in the books and magazines I grew up with.

A good overview of the various distortion tones:

http://www.gmarts.org/index.php?go=217


At the bottom of this page you'll find some great details about various distortion circuits:

http://www.geofex.com/effxfaq/distn101.htm


I have a big home made pedal board with a power supply etc. and I also just mix and match single boxes. I often times daisy chain distortion boxes and usually have a compressor available.

Here's some stuff that is out of the big plastic toy box and laying around on the floor right now:

distortion:
Ibanez Tube Screamer
Pro Co Rat
EH Big Muff Pi
DOD Flashback Fuzz
Ibanez Super Tube

compressor:
Boss CS-1
DOD MilkBox

stuff:
DOD FX25 Envelope Filter
EH Bass Microsynth (great for guitar)
DOD Phaser
DOD Ice Box Chorus

A few old wahs.


Personally, I'd rather have the whole range of distortion palettes than 1 single 4 channel all tube (with a few transistors hidden inside for distortion) holy grail 1,000,000,000 watt head.

Two distortion pedals daisy chained into a 3 watt Champ is the sound of MAYHEM. Shove an envelope filter in and you can make windows quiver... or the sound of melting metal. etc. etc.

Some people recognize these great tones as vintage.... because they have heard these tones countless times on records. I'm of the opinion that playing an electric guitar will remain perpetually modern... I think it is an activity much like flying a jet plane... it will always be a "modern" activity.

The fact that it is an affordable activity makes the idea of pushing the experience of playing in an electric style it too it's limits even more attractive to me. I can't afford a jet plane... playing funky loud distorted guitar is something I can do with abandon. It's a cheap thrill.

Lately I have been primarily fascinated with simply swapping guitars and playing straight into an amp. I've come to savor the difference between each guitar's pickups and how they can make the amp break up. A pickup to tube connection is like a taught springy string... It's very dynamic feeling. That's something that you can never get with a model.

Anyways, I'm babbling now.

I really hope you'll make some time to read the bottom portion of RG Keene's web page where he lists circuit topologies and resulting sound characteristics. It should open you eyes to the potential variety that exists when you start mixing and matching these tones.

best regards,
mike

Ron, you are a great player!!!

I want to politely disagree with you.. The new amps may not say they require biasing... but that is only because they are set up somewhere in the middle of a common range that is thought to compliment today's new tube stock.

The example I cited above about that Princeton didn't involve actual adjustments... just observations. If I leave the tubes running 33mA in there I'm OK to go, but If I leave the set from the same stock that drew 39mA there is going to be a melt down.

Are you aware of any new amps that have some form of current regulation on the cathodes? I'm not... maybe that is something that is new?

I have, in the past, swapped tubes in my cathode biased Champs without making observations or adjustments and it has been ok... but I wouldn't use that experience to conclude that it is safe practice.

Anyways, I got a bunch a parts for a DIY AX84 P1extreme amp from my UPS driver just last night... keep an eye out for an up coming thread.

all the best,
mike

Here's a great link on tube biasing Tube Bias Setup .

Nice, Mike ... A whole lot of stuff there. I think I recognize many of those books.I didn't see the old RCA Tube Manual, though!