New To The Forum...

[T Wilcox]

nevermind

[Murali]

nevermind

Please accept my apology, rooster! I've abused your goodwill. I admit to being curious to see if that's just the way this forum goes: one posts a "new to the forum" post and gets a single reply... until you insult someone.

Why criticize until you've tried the mods? They work very well and don't compromise the character of the amp or Ken's design. The controls are on the outside of the amp and can be adjusted on the fly.

To SURFSUP: Adding resistance here reduces the hiss, lowers the gain and reduces the "touch sensitivity" of the amp. It is very useful for cleaning up the sound and for using the amp in small venues. Yes, it DOES change the character of the amp as you add the full 250k in series, yet it still sounds very good.

The switchable Treble cap is not a bright switch, per se. Seems like rooster misread that - probably my fault. This switches in/out a second 250pf cap in parallel with a more common 250pf treble cap in the tone stack, to give one the option of using Ken's 500pf or the Fender-style 250pf.

IMHO these mods just make the amp more versatile and useful. Once you've tried one or all of them, I would be very interested in your comments.

Thanks to all who have replied.

[rawnster]

The switchable Treble cap is not a bright switch, per se. Seems like rooster misread that - probably my fault. This switches in/out a second 250pf cap in parallel with a more common 250pf treble cap in the tone stack, to give one the option of using Ken's 500pf or the Fender-style 250pf.

No Rooster didn't miss read you. Changing out the 500pf for a 250pf shifts the mid freq response (boosting it too high). Try the Duncan Tone Stack Calculator, and you'll see what I'm talking about.

[Murali]

The switchable Treble cap is not a bright switch, per se. Seems like rooster misread that - probably my fault. This switches in/out a second 250pf cap in parallel with a more common 250pf treble cap in the tone stack, to give one the option of using Ken's 500pf or the Fender-style 250pf.

No Rooster didn't miss read you. Changing out the 500pf for a 250pf shifts the mid freq response (boosting it too high). Try the Duncan Tone Stack Calculator, and you'll see what I'm talking about.

thanks rawnster. But you guys with your theoretical stuff.... You really need to try it and listen. The real-world result is what is significant (to me). It is much more subtle than "shifts the mid freq response (boosting it too high)" implies.

What I'm after is being able to shape the tone and response to suit the application and venue. Otherwise, why have tone controls? Or any controls?

[Reeltarded]

Amen to that!

You be quiet. Where's that amp?

[rawnster]

What I'm after is being able to shape the tone and response to suit the application and venue. Otherwise, why have tone controls? Or any controls?

What? No one here lives in a vacuum. We're all looking to build amps for certain applications. It seems like you're not willing to listen or take advice. Good luck with your amp.

[Murali]

Amps

Hmmmmmm. What do I know about amps? I started formal, academic studies of electronics with emphasis on tube technology in school in 1971. I've tinkered with them ever since, but I don't have anywhere near the knowledge of rooster. I read his posts (and many by other TAG power-users) and feel like a hummingbird that just scored a huge jackpot of flower nectar. Compared to him, I'm a complete hack.

Recording

I began multi-tracking when the Teac 3340s hit the scene. Have used various "Portastudios" and DAWs since those days. I have performed and engineered tracks released by roughly a dozen artists. I prefer to mic a good tube guitar amp and track it. But I've had to use digital emulators and solid-state boxes by demand of producers too. I don't like them, but I can use them. I've never had the privilege to run a big Neve or SSL console with a couple of 24 track analog tape machines slaved together, like some folks around here. In contrast to that level of experience, I am again a complete hack.

Performing

Been picking guitars for 40 years now. Semi-professional for 30+ (meaning I get paid for it, albeit not enough to support my family .... thus the day-job). I've played in the high-hundred's of gigs .... but not thousands like some folks hereabouts. I've played as a sideman for a multi-Grammy winning artist; a gifted, talented, wonderful performer. But I don't have her talent, stage presence, or charisma .... so I'm not the one in the spot-light .... and I'm completely okay with that. It has always been a supreme honor to play music for folks ..... whenever and wherever. Even though I am a relative hack at it, I show up on time, sober, prepared and ready to fulfill the code-of-the-road.


But I can't answer your technical amp questions. I've still got a LOT to learn. I'm extremely grateful for folks like rooster (and just about everyone here at TAG) for the incredible generosity to share knowledge and expertise. Thanks to all of you!

Nick, thanks for your post. I appreciate you taking the time to reply in such detail. Sounds like you've had a long and interesting musical life. I'd love to hear some of your work. Any of it online?

Please take a moment to listen to my stuff. You can search it on iTunes under "Enjoying A Life" and iTunes lets you preview over a minute. All the guitars are recorded with amps I've built.

[Murali]

What? No one here lives in a vacuum. We're all looking to build amps for certain applications. It seems like you're not willing to listen or take advice. Good luck with your amp.

Rawnster, you're funny! Who's not willing to listen or take advice? I post something that works for me and I'm told that it can't be any good. And you tell me it can't be any good because a chart is telling you it can't be any good.

Do the mods in your Express, then you can criticize and let me know how much you hate them.

[FuzzFreak]

Nick, thanks for your post. I appreciate you taking the time to reply in such detail. Sounds like you've had a long and interesting musical life. I'd love to hear some of your work. Any of it online?

Please take a moment to listen to my stuff. You can search it on iTunes under "Enjoying A Life" and iTunes lets you preview over a minute. All the guitars are recorded with amps I've built.

I think what you missed by Nick's post is that he is here with humility, like the most of us here. Your sarcastic and pompous responses are not going to impress anyone, especially some of the guys on here who have been around the block 12 times since breakfast. I'm sure Nick's work, like anyone who appreciates their music, is online... but coming back with a 'im going to be sarcastically nice and my music is probably better than yours' response.

And I am sure all 11 (that's right everyone, 11) people who like you on facebook enjoy the way your amps sound. Oh wait here is that facebook link: http://www.facebook.com/pages/Murali-Levine/94492273113 I won't go into having to soak my ears in Epsom Salt for a few hours after listening to how much you enjoy life earlier today.

Sometimes you have to be nice to get what you want, and unless you put yourself above everyone else, everyone here will respect you. Guys like you are the reason most of the REAL amp builders have stopped coming around. Listen. Respect. Apply.

Best of luck to you, Steve!

[Murali]

I think what you missed by Nick's post is that he is here with humility, like the most of us here. Your sarcastic and pompous responses are not going to impress anyone, especially some of the guys on here who have been around the block 12 times since breakfast. I'm sure Nick's work, like anyone who appreciates their music, is online... but coming back with a 'im going to be sarcastically nice and my music is probably better than yours' response.

And I am sure all 11 (that's right everyone, 11) people who like you on facebook enjoy the way your amps sound. Oh wait here is that facebook link: http://www.facebook.com/pages/Murali-Levine/94492273113 I won't go into having to soak my ears in Epsom Salt for a few hours after listening to how much you enjoy life earlier today.

Sometimes you have to be nice to get what you want, and unless you put yourself above everyone else, everyone here will respect you. Guys like you are the reason most of the REAL amp builders have stopped coming around. Listen. Respect. Apply.

Best of luck to you, Steve!

OK, now the real flaming begins! Thank you FuzzFreak. So, just to refresh your memory, here is my FIRST post to your beloved forum:

Hi,
This is my first post, though I've used this forum as a resource. Thanks for all the great info and schematics, much appreciated.

I recently built a 'wreck and made some mods to the circuit that I've found very useful. They've probably been done and posted here before, so please excuse me if I'm being redundant.

I've done three things based on Version A1a of the wreckxpr.pdf schematic using EL34s:
1. I made the 500 pf cap to the Treble pot switchable to 250pf.
2. I inserted a 250kB pot in series with a 56k resistor in place of the 100k slope resistor in the tone stack, and
3. I inserted a 250kA pot (in series) between the 10k cathode resistor on the 3rd gain stage and ground.

Of the above mods, #3 has been the one I use the most, although the other two can alter the character of the amp nicely, too. I gig and record regularly and enjoy using and experimenting with amps I've built. I've also built a version of the Trainwreck above with a 2 EL84 Cathode Biased output 'cause the EL34 amp is too loud to use here in the clubs of Santa Fe, NM.

Being able to vary the sensitivity of that last gain stage is very useful and I've measured and marked settings of the pot that yield unity gain and also the output of a cathode follower. Using this in conjunction with the 250pf Tone Stack cap and adjusting the slope resistance results in being able to approximate some Fender amp tones.

I'd love to hear what you guys think of these mods. Or to know if they've been around before.
All the best,
Murali

[T Wilcox]

[quote="Murali"]You all know this "rooster" person is full of crap, don't you? [hey, nothing personal, rooster.]

Now, could I please hear from any of you who actually know something about amps, recording and performing?


Just a reminder of your next post.


Todd

[M Fowler]

I haven't seen those mods on an Express but have seen the slope resistor with trimmer and trimmer for V1a plate resistor and tail resistor with trimmer on a Rocket type amp. You could dial in some nice overdrive.

For a type of volume control mod the watts control I used the following attachment. The mod just varies the gain of the PI tube.


Mark

[dreric]

Mods....................can we just lock this now?

e

[Murali]

I haven't seen those mods on an Express but have seen the slope resistor with trimmer and trimmer for V1a plate resistor and tail resistor with trimmer on a Rocket type amp. You could dial in some nice overdrive.

For a type of volume control mod the watts control I used the following attachment. The mod just varies the gain of the PI tube.


Mark

Thanks, Mark. One question: doesn't the 33k across the pot make the effective value of the pot about 14k?

[M Fowler]

doesn't the 33k across the pot make the effective value of the pot about 14k?

The resistance in parallel is 1/(1/Ra + 1/Rb) per my good friend.

This is what Egnator used in his watts control and you can see this similar use on the Carlsboro 60TC labeled limiter.