I'm tired of anemic guitar amps!

[Chuz Life]

Okay, the first two are definitely doable with Twins. The third one is punchy, it has a lot of pick attack. I suspect there was a pedal involved, on that one. SRV is difficult to achieve with a single amp, as close as "I" get is the Dumblator concept with the gain set just on the edge of breakup. SRV used one of the Dumble's with the switchable Twin-T filters for midrange control, if you're feeling ambitious you could try that. He also used 15" speakers though, I think that was a big factor in his sound.

That's Albert Lee on the third one and I see him playing lots of different amps.

There's no way to know what they do in the studios. I do like some of that pick attack, quack, etc.

To answer one of your earlier questions, I hardly ever play the clean channel but I do when and if I use any effects pedals.

 

[Chuz Life]

A couple of thoughts - as long as you have two of these - if it were me, I'd keep the good sounding one in original condition and use the other one as a modding platform. I'm going to guess you have the ultralinear version, it was most popular and very successful. This one:

https://schematicheaven.net/fenderamps/twin_reverb_sf_135_schem.pdf

If it's the one I think it is, it'll have a bunch of white wiring that looks a little messy. First thing is, disconnect all the wires to the pull boost, there's 4 of them, on the schematic the first half of the switch is to the right of v1b, it's across a 1 meg resistor. The other half of the switch is at the bottom left in the reverb circuit, coming off the top side of the reverb transformer. I would snip the wires on the other side.

Then, you have two channels - do you use them both? I never use the clean channel, just the reverb. So I disconnect the other side of the .047 capacitor coming off the plate of v1b, at the junction of the 220k resistor, and feed it into the input at v2a. Then I futz with the input jacks on the reverb channel, so when nothing is connected there and the guitar is plugged into the clean channel, the signal goes all the way through V1 and then through V2. This way v1 becomes kind of like a Dumblator. But if the guitar is plugged into the reverb channel instead, it's still the normal reverb channel.

This mod will give you way more gain than you need, and this is where the midrange mods really shine, because in high gain mode the first tone stack in v1 determines your gain character, and you'd like lots of mids and very little at the edges, that'll give you good responsiveness without bumblebees or ice picks. Then you still have the second tone stack for your overall sound.

I took a closer look at that schematic, and I got a chuckle out of the Power Transformer drawing.

I know why (probably) they drew it the way they did. . . but I wonder how many other techs over the years have noticed that they drew it so the Higher Input Voltages are connected to the higher number of turns on the primary (opposite of what the inputs should be.)

 

[Fort Fun Indiana]

A lot of players love setting the amp on "edge of breakup".

Handy in the studio, but not so handy for the average working musician who doesn't get to or want to play at high volume levels.

I get what I feel is the exact same effect by just using the setting on the amp specifically made to acheive the breakup sound: the "crunch" channel, on modern amps.

Set the gain at maybe 1:00 and use the guitar's volume knob to achieve the same effect at any amp volume. This works especially well with modern guitars with treble bleed circuitry.

 

[Chuz Life]

This is interesting history!

The earliest radios used no tubes at all, they were just fancy crystal radios. The first ones used a "galena whisker" as a diode.

When the tubes came they first needed batteries, because no one had AC yet, and in some places it was even DC. But when AC came to the home, there were companies that wanted everyone to buy their cheap radios, and they didn't want to use transformers because they were half the cost of the whole device. So they went through a period where they tried to power everything straight off the wall. And this meant, they had to wire the heaters for the tubes in series, because no 6.3 volts because no transformer.

So this is when cathodes became popular, because suddenly you had heaters sitting 50 volts above ground.

This idea of powering straight off the wall resurfaced several times. When the first 7 and 9 pin miniature tubes started coming out, there were a lot of compact radios from that period with no transformers, and tubes like 50C5, 35W4, and so on. Then the idea resurfaced again when the ultra-mini tubes came out and the radios got even smaller, because Eveready and Duracell weren't in all the 7-11's yet.

I remember building a geiger counter when I was 9 or so, it used a 45 volt battery to power the photo multiplier tube. I had to go the electronics store to buy one and they had to special order it.

Hm. Once I tried powering a 100 watt amp off my car, with an inverter. It lasted about half an hour.

This video reminded me of this post.

 

[Chuz Life]

Well, I managed to get the bench stained and clear coated (several coats.) It's not perfect, but it's a better bench than what I had!

I have a pretty long "things to do" list. Some of the test equipment seen here is in need of repair or mods. So, I'm probably going to start a whole new thread, so I don't keep derailing this one.

 

[toobfreak]

Well, I managed to get the bench stained and clear coated (several coats.) It's not perfect, but it's a better bench than what I had!

I have a pretty long "things to do" list. Some of the test equipment seen here is in need of repair or mods. So, I'm probably going to start a whole new thread, so I don't keep derailing this one.

View attachment 1224485

Lookin' pretty fargin' good! I see you have Fluke 80 series multimeter there, maybe a model 86? And whoops, there's that variac on the left. Only thing I might add right away is to get a grounded ESD mat for added protection.

Oh and, you'll need some music too so you need to get some sort of stereo going so you can mount a speaker on each end of the bench. Soldering is so much more fun with tunes to listen to.

 

[Synthaholic]

For electronic parts I usually go to tubesandmore.com, they stock all the essentials.

Have you ever used Groove Tubes? The inventor was a friend. He passed away about 7 years ago in an L.A. car accident.

 

[Chuz Life]

Lookin' pretty fargin' good! I see you have Fluke 80 series multimeter there, maybe a model 86? And whoops, there's that variac on the left. Only thing I might add right away is to get a grounded ESD mat for added protection.

Oh and, you'll need some music too so you need to get some sort of stereo going so you can mount a speaker on each end of the bench. Soldering is so much more fun with tunes to listen to.

The fluke is a model 87, I plan to add a current limiter to the variac, I have an ESD mat but frankly, I've never had an issue (knock on wood) from not using it.

I haven't even started on a PC and speakers. I'm trying to use what I have rather than throw more and more money into it, but I do already have a small touch screen monitor to use for schematics. But I haven't found a boom or long reach arm I could use, so that I can move it around.

I get so overwhelmed, I can't even describe it. The desolder station is way overkill for anything I do (and it needs some work.) Plus, I don't like all the chords lying there.

But, there it is.

At least it's solid and roomy.

I'll start a new thread soon, and I hope others will share their bench pics too!

 

[scruffy]

Have you ever used Groove Tubes? The inventor was a friend. He passed away about 7 years ago in an L.A. car accident.

I met Aspen. He gave me a guided tour of his facility in Sylmar.

 

[scruffy]

I'll start a new thread soon, and I hope others will share their bench pics too!

I need a bench. And a place to put it.

In OK I have practically the whole basement to myself. Here, there's about a quarter of a room without clutter, and right now it's filled with computer boxes.

This is a serious problem! A tech without a bench? Gotta solder on your lap? Or on the floor? Either way you end up with solder in the fabric. Hey, that's a new look, leftards might like it. But then I'd have to get a nose resistor or something.

 

[Synthaholic]

I met Aspen. He gave me a guided tour of his facility in Sylmar.

He was a great guy. We spoke on the phone about a week before his accident. He wanted me to be a part of his Spacestation ad campaign. I bought a first generation model, and I use mine a lot. Aspen told me that he didn't know anyone else in the world who used it as frequently as I do. We were talking about him developing a smaller version for quieter settings. I love my Spacestation v3. Stereo out of a single cabinet and sounds fantastic. But I've never needed to turn the volume higher than 10 o'clock. It's a loud sucker. Too loud for my needs. Hence, the discussion about a smaller, lighter model to go with the larger Spacestation XL.

As for your OP, I've never been a fan of 'The Marshall Sound'. I've played with a lot of guitarists over the decades and my favorite tones were from Orange, Ampeg, Fender Twin Reverb (as long as it wasn't close to me), and especially Mesa/Boogie. Even Peavey had some good guitar amps. PAs weren't worth a shit.

 

[Chuz Life]

I need a bench. And a place to put it.

In OK I have practically the whole basement to myself. Here, there's about a quarter of a room without clutter, and right now it's filled with computer boxes.

This is a serious problem! A tech without a bench? Gotta solder on your lap? Or on the floor? Either way you end up with solder in the fabric. Hey, that's a new look, leftards might like it. But then I'd have to get a nose resistor or something.

I might just have to steal and patent the nose resistor idea!

 

[toobfreak]

The fluke is a model 87,

Yeah, the 87 had a few extra features like capacitance I think.

I plan to add a current limiter to the variac, I have an ESD mat but frankly, I've never had an issue (knock on wood) from not using it.

ESD is kind of ingrained in me. For a time, I worked in a electronics research lab and you could get fired for not wearing and using an ESD strap. But most electronics not based in heavy microchips, etc., usually is pretty impervious to ESD.

 

[Chuz Life]

Yeah, the 87 had a few extra features like capacitance I think.


ESD is kind of ingrained in me. For a time, I worked in a electronics research lab and you could get fired for not wearing and using an ESD strap. But most electronics not based in heavy microchips, etc., usually is pretty impervious to ESD.

I use it for added insurance when working on other people's stuff. For my own I prefer a piece of material like a floor mat or outdoor carpet.

 

[Chuz Life]

I need a bench. And a place to put it.

In OK I have practically the whole basement to myself. Here, there's about a quarter of a room without clutter, and right now it's filled with computer boxes.

This is a serious problem! A tech without a bench? Gotta solder on your lap? Or on the floor? Either way you end up with solder in the fabric. Hey, that's a new look, leftards might like it. But then I'd have to get a nose resistor or something.

In machine maintenance, we techs had to use the tops of our roll around toolbox for a bench. (harbor freight mostly but some had Kennedys) There was a lot of creative ideas from others based on what each of us gravitated towards.

 

[scruffy]

I just got a real neat chip in the mail, it's a voltage controlled prism. With a frequency to voltage converter, you could set it on top of the amp, that way it'll respond to both your playing and the stage lights.

 

[Chuz Life]

I just got a real neat chip in the mail, it's a voltage controlled prism. With a frequency to voltage converter, you could set it on top of the amp, that way it'll respond to both your playing and the stage lights.

Do you have a pic?

Link?

 

[scruffy]

Do you have a pic?

Link?

Yes. However I just buried it under a bunch of boxes. If you'll give me a minute to organize my life I'll rescue it. Might take a couple of hours. How about "sometime today".

 

[Chuz Life]

Yes. However I just buried it under a bunch of boxes. If you'll give me a minute to organize my life I'll rescue it. Might take a couple of hours. How about "sometime today".

Just curious about what it is.

 

[scruffy]

Just curious about what it is.

It's a tiny photonic version of something I built a long time ago. It basically changes the angle between two faces of a prism, based on voltage control. I'll have to spend an hour with the box cutter when I get home, I'll show you. It's just a chip, looks like an FPGA with a couple of bumps.