How about guitars?

[AnotherJohnson]

More amp fun! I’ve been wrestling with a vintage vacuum tube amp this week. The output tubes are 6L6 GC, and the preamp is 12AX7 - 12AT7 - 12AX7 - 12AT7. The rectifier is an RU4GB.

It is a 40 watt class AB amp. With guitar amps you’re looking for pleasing distortion rather than perfect reproduction of the input signal.

Next up is a 35 watt class A amp, based on 6V6 output tubes.

I’ve also got a 50 watt based on EL34s.

After playing for an hour, even the best of recordings leaves room for improvement.

[roberto]

Tubes are tubes... they really have a kind of magic. The 6L6 was used by Fisher and Gerald. McIntosch did use them too. Also Marantz and Mesa. Many brands, as I do recall. The 5881 used by Mesa Baron, and a French brand, Jadis.

Happy listening¡

[AnotherJohnson]

I picked up a used Rivera Venus 6 the other day.

It’s 35 watts class A based on four 6V6 output tubes.

It has a Vintage/Modern switch on the back. Vintage mode is 17 watts class A.

The manual says the switch sets the output stage up in Triode mode. Modern switches to Pentode.

[AnotherJohnson]

The VVT amp turns out to be self biasing. That makes it even easier to maintain.

The Rivera’s have a bias pot, require matched output tubes, and won’t give out official info because they don’t want newbies poking around inside the amp with 400 to 500 VDC on some of the caps.

In the audio world, I think Chinese made Prima Luna advertises self biasing. The US made Audio Research requires matched output tubes, so they must use one pot per pair or quad. CJ used individual bias pots on the pre ART tube amps (in my experience), but I think they’re using the matched tube approach on the ARTs. I should look it up.

With the guitar amps, since the goal is not to necessarily follow the input signal exactly, biasing is very forgiving. It looks like you’re trading off clean tones against dirty, and both may be desired. Dirt comes from blowing through the headroom, which is impacted by the bias point.

In an audio amp you really do not want dirt. Just pristine clean ... near perfect following of the input.

[roberto]

Self bias has been for some time. Margules Audio, made in Mexico, do have auto bias. Talk to Julian, the owner, and tell him that I told you so.

He is a very humble man, and his U-280sc is a beauty. Not too power, but real sound. I love it.

Happy listening!

[AnotherJohnson]

Roberto wrote:

Now I want a Hoffner Beatle violin bass, with ebony finger board. I have a Cavern model, and it is fun to play. Now I just want a better one. I have my eye at EBAY, and sometimes good things are a bargain prices. The problem is, that you must see what you are buying...I have bought in the past bad things.
Enjoy your guitars!!!'


**********
Yes, eBay is a mixed bag. With guitars it is always better if you can try before you buy.

If the price is low enough, sometimes it is worth the risk.

I used to look for guitars that were priced low because the seller didn’t realize that set up problems could be fixed.

I’ve ordered an octal tube tester for all the guitar amp tubes of uncertain condition. It will do the power tubes in all of my amps. EL34, 6L6, 6V6 ... and more.

I’ve been refreshing my knowledge of guitar amp circuit design. We come back to the subjective nature of guitar and guitar amp evaluation. Very different from evaluation of audio system component evaluation.

One thing’s the same though ... if it sounds good to you, it’s good for you.

[AnotherJohnson]

Self bias has been for some time. Margules Audio, made in Mexico, do have auto bias. Talk to Julian, the owner, and tell him that I told you so.

He is a very humble man, and his U-280sc is a beauty. Not too power, but real sound. I love it.

Self biasing seems like a nice idea, but the way it seems to be done looks imprecise to me. Basically, you’re trying to set it up so that the difference between cut off and saturation is split evenly. But with a fixed cathode bias, you neglect tube to tube variations, as well as pickups and playing style. It’s probably not a big deal for guitar amps since they’re not supposed to exactly follow their input, and since in many cases you have three volume/gain controls per channel (guitar, volume/gain, and master volume. How you set these impacts the distortion... and distortion is part of the sound profile. I think that’s why I like clean tones as you shoot for in jazz, rather than crunchy tones as you have in Heavy Metal.

[roberto]

Oh yes,
When I was a kid, I had a Silvertone power amp, I did use two 6L6. Well, when I wanted to play real ugly, what I did was to take off one power tube. What a distortion!. This horrible sound was sent to a Teisco Bass power amp. I had a switch to by passed the Silvertone. What days...I can't believe that I did that. I was a teenager of course. Then the Fuzz tone device came out, and I started to use that. My ears was accustomed to the distortion of the Silvertone, but I decided that I should kept the fuzz tune. Also at that time, the wah-wah came out. Been fan of the Beatles, I had later the Beatle power amp, and the Westminster for the bass. I remember that this one had an eighteen inches woofer. My guitars were made in Italy, also made my Vox, and some Fender. My friends also had different guitar brands, trying to emulate that Beatles and Rolling Stones sound. What a fun.

Because their reliability was not too good, I started to enter into the world of electronics, been just a kid, soldering cables, and broken solder joints, easy things...my dad was very knowledgeable in electronics, and I started to study since then...

[AnotherJohnson]

In a push pull amp, pulling a tube removes half the wave. The asymmetrical clipping is unpleasant... unless it’s your choice to produce it.

I remember the first time I heard a fuzz box. I thought it was really cool.

There was a lot of experimenting with effects in those days. I think we were attracted to the bizarre rather than to the accurate.

[roberto]

You can't imagine the distortion, poor power amp! And what amused me was, it did not burn doing that. I replaced the tube, and started to sing as it should. Agreed with you, those days were crazy.
Now I have my eye on that Hofner Beatle bass. It has ebony fingerboard. I do like ebony. Besides the look, the sound is much better. I do not the why is this, I have a friend who owns one, and the feeling and sound is different than the one that I own. It is just for the fun to play it.
One of the guitars had 12 strings, tune tone, and fuzz tone. It used a 9V battery. Vox Italy made. Color was like dark red wine.

[AnotherJohnson]

You mention cables. The cable does have a big impact on the sound. I’ve got several from Mogami, Klotz, and others. They all sound different, but the cable, and pickups and amp all function together to create the instrument.

JF once told me that the source preamp amp and speakers were all in it together as one unit. This was the conversation when he suggested I should be plugging the electronics all into the same duplex outlet. Great advice that did improve my sound for free.

[AnotherJohnson]

Another little amp I picked up recently is a solid state “modeling” amp built in China. It’s the Spark 40 by Positive Grid. Very inexpensive, very light to carry, very flexible (it can be paired to sources by Bluetooth and used as a remote speaker).

It’s much better than it has any right to be at its price point. Since it’s so easy to transport, I’m using it as a travel amp.

[AnotherJohnson]

I’m finalizing a deal tomorrow...

My shoulders are really limiting my ability to enjoy more than five or ten minutes at a time playing my thick body guitars. I’ve always preferred to play in the formal classical posture, but this is just not feasible anymore. I don’t know how Segovia managed it into late life. Historically, my Strats, Teles, Les Pauls, ES335s, Dreadnaughts, etc disagreed with the classical position, and that may be why the only two guitars I’ve kept, up until now, have been my L5CES and my Collings OM3.

Not too long ago, and my incentive for starting this thread, I acquired a new Strat, and found a way to play it with more comfort, contrary to the classical position.

I’ve had so much fun with that Strat that I’ve worked a deal to trade the OM3 for three additional late model Strats. I know you can just play one at a time, but with several locations where I play/practice, more Strats means less carrying of Strats around.

This trade looks like one where both parties will be thrilled with the result, and those are always the best kind of trades.

One is a 1955 Vintage Custom Shop reproduction, one is a limited edition American Deluxe, and one is an American Professional. By this time tomorrow we should be done.

Then it will be time to decide which ones to keep.

[drinkwine]

I have a 76 Guild D-50, 2006 Goodall Concerto, and a '73 Hagstrom. But now I hardly touch them. It's all about my 1911 Steinway A. That's all I have time for.

[AnotherJohnson]

One really nice thing about the piano is that the 88 notes are each unique. 12 notes of the chromatic scale, repeated for 7+ octaves. 880 Hz appears once on the keyboard, so when you see it written on a ledger line, you know that there is only one correct key to play.

The piano is really the best place to learn about music theory.

The guitar is a bit strange. On a typical modern electric guitar, there are over 120 places to play notes, but less than four octaves worth of unique notes. So, if a note appears on a ledger line, there will probably be several possible places to play it, and which one to choose depends on where your hand already is.

Tal Farlow was known as The Octopus because his hands were so large that he could make spans that others could only dream about.

In any event, the Steinway is a great playground, and unless your house is the size of a museum, Steinways defy most collecting impulses. One or two is usually enough. We have my Mother’s Mother’s Spinet. I’ve tried to donate it to several charities. No one wants it. I gave away an 1890’s era saloon/dance hall pump organ to a sentimental old guy (he is actually younger than me ). But no one wanted that either.

Steinways seem to maintain some respect and collectibility. But most in the modern era seem to be choosing electronic keyboards as their initial learning platform.

With guitars, most who become enamored with the instrument also end up with multiple samples.

[AnotherJohnson]

Today I thinned the Stratocaster herd. I have one left … the 1955 Custom Shop reproduction.

The “new” guitar is a 1963 Gibson Barney Kessel model. My arthritis doesn’t like it. But as a serious Barney Kessel fan, I had to trade for it.

1963 was the year I got my first Gibson guitar. I traded my Stella for it. I was in Heaven.

609B72C2-88D5-49DB-BE59-4F57562D8316.jpeg (3.63 MiB) Viewed 3527 times

It’s thinner than my old L5CES. Painful to play, but not as bad as a dreadnought.

[AnotherJohnson]

I got to talking with my friend Jack Pearson today. He’s released quite a bit of material for down loading recently.

Here’s a link

https://jackpearson.bandcamp.com/

[admin]

Beautiful guitar. Not just an instrument but a work of art. Congrats.

[roberto]

That guitar is a truly jewel. Can you bring the strings down, almost touching the nec? This tweak will make to softener the play...just thinking loud.

A truly beauty!!!

[AnotherJohnson]

The set up is actually quite good for me (low).

But I will make some adjustments when I change the strings to LaBella Jazz Flats. Intonation is perfect. Frets are as new, so probably recently refretted. The neck is a very tight grained piece of quartersawn mahogany, straight and true. The back inside grain looks carved, but the top may be laminated. I will have to take my flexible borescope and look at the back side in the interior to compare grain. The top surface of the top is pretty tight grained spruce. It’s double bound. The top is lively, which suggests that it might be carved. The original pickups sound wonderful through any of my amps.

I wish it didn’t hurt to play, but “whatcha gonna do?”