Egnater Seminar Fun (w/Pictures!)

[Anonymous]

Welcome to the club, Steve - congrats and thanks for sharing the pics with us.

Thanks Olaf! Now at least I know how to fix my preamp and how to design the rest of my amp!

Steve

 

[Anonymous]

So got any cool info you could share like how the tone stack works in the circuit, and maybe some info on PPIMV's?

I sure do, however, it would be difficult to explain how the tone stack works without you having a frame of reference. You'd need the schematic so I could tell you what components effect tone and in what manner. Suffice it to say that plate resistors have a huge affect on gain of a stage - the higher the value, the higher the gain (however there are other tradeoffs and you have to be careful about the size of the cathode resistor). Cathode and coupling caps can have a big impact on bass response - higher cap values = more bass - gotta be careful here as well though because if you have a high gain amp with alot of bass being amplified in early sections of the pre it is gonna get muddy at best or motorboat at worst... With high gain circuits you have to carefully consider your filtering in each stage of the design...

Whaddaya wanna know about PPIMVs? The circuit we built didn't have one, but Bruce gave us a schematic to add one if we wanted to... For the seminar amp though, I don't think it is needed...

Steve

 

[gravfed]

Wow, that looks killer. Thanks for the review. I think I def. need to put that on my "to do" list!

 

[tweed]

So got any cool info you could share like how the tone stack works in the circuit, and maybe some info on PPIMV's?

I sure do, however, it would be difficult to explain how the tone stack works without you having a frame of reference. You'd need the schematic so I could tell you what components effect tone and in what manner. Suffice it to say that plate resistors have a huge affect on gain of a stage - the higher the value, the higher the gain (however there are other tradeoffs and you have to be careful about the size of the cathode resistor). Cathode and coupling caps can have a big impact on bass response - higher cap values = more bass - gotta be careful here as well though because if you have a high gain amp with alot of bass being amplified in early sections of the pre it is gonna get muddy at best or motorboat at worst... With high gain circuits you have to carefully consider your filtering in each stage of the design...

Whaddaya wanna know about PPIMVs? The circuit we built didn't have one, but Bruce gave us a schematic to add one if we wanted to... For the seminar amp though, I don't think it is needed...

Steve

I dunno exactly. I put a PPIMV in my bogen vplexi, it's one from the metroamp forums, and it sounds damn good. Im wondering if there is maybe some secret we don't know about for PPIMV's that could possibly make it better.

I am currently going thru the bogen and talking with Olaf about a few things. Maybe change the filtering a bit and bump the gain up slightly. I am really new to this stuff but im reading everything I can get my hands on lately. As soon as I get a little better handle on this stuff im going to start modifying this old grey amp I have at home. It has HUGE transformers and a pretty sizeable chassis, so hopefully i'll be able to put some sort of rodded plexi circuit inside but we'll have to wait and see.

 

[Anonymous]

So got any cool info you could share like how the tone stack works in the circuit, and maybe some info on PPIMV's?

I sure do, however, it would be difficult to explain how the tone stack works without you having a frame of reference. You'd need the schematic so I could tell you what components effect tone and in what manner. Suffice it to say that plate resistors have a huge affect on gain of a stage - the higher the value, the higher the gain (however there are other tradeoffs and you have to be careful about the size of the cathode resistor). Cathode and coupling caps can have a big impact on bass response - higher cap values = more bass - gotta be careful here as well though because if you have a high gain amp with alot of bass being amplified in early sections of the pre it is gonna get muddy at best or motorboat at worst... With high gain circuits you have to carefully consider your filtering in each stage of the design...

Whaddaya wanna know about PPIMVs? The circuit we built didn't have one, but Bruce gave us a schematic to add one if we wanted to... For the seminar amp though, I don't think it is needed...

Steve

I dunno exactly. I put a PPIMV in my bogen vplexi, it's one from the metroamp forums, and it sounds damn good. Im wondering if there is maybe some secret we don't know about for PPIMV's that could possibly make it better.

I am currently going thru the bogen and talking with Olaf about a few things. Maybe change the filtering a bit and bump the gain up slightly. I am really new to this stuff but im reading everything I can get my hands on lately. As soon as I get a little better handle on this stuff im going to start modifying this old grey amp I have at home. It has HUGE transformers and a pretty sizeable chassis, so hopefully i'll be able to put some sort of rodded plexi circuit inside but we'll have to wait and see.

I certainly don't know of any secret to PPIMVs...

If you really want to get into this and aren't going to be able to attend Bruce's class, I really recommend you get the Torres book I mentioned in my initial post. It explains filtering and how to bump up gain, etc... It is a great, detailed book with example projects you can try. It basically covers all sections of a tube guitar amp with how to design/mod each section...

Steve

 

[tweed]

I certainly don't know of any secret to PPIMVs...

If you really want to get into this and aren't going to be able to attend Bruce's class, I really recommend you get the Torres book I mentioned in my initial post. It explains filtering and how to bump up gain, etc... It is a great, detailed book with example projects you can try. It basically covers all sections of a tube guitar amp with how to design/mod each section...

Steve

Thanks Steve, i'll look around for the book. I was initially going to try and attend the May class, but then the ortho bill for my son hit and that idea flew out the window lol.

 

[tweed]

Book is ordered.

 

[Gainfreak]

Book is ordered.

Dude, you have been wanting to buy that book for over a year now!! Glad to see that you finally got it

 

[tweed]

Book is ordered.

Dude, you have been wanting to buy that book for over a year now!! Glad to see that you finally got it

Actually a buddy let me borrow his a while back so I didn't purchase it then. But have since given it back and forgotten everything that I read! So now I be needin' my own copy and stuff.

 

[Gainfreak]

Book is ordered.

Dude, you have been wanting to buy that book for over a year now!! Glad to see that you finally got it

Actually a buddy let me borrow his a while back so I didn't purchase it then. But have since given it back and forgotten everything that I read! So now I be needin' my own copy and stuff.

 

[Digital Jams]

Shit...............Randy is on month 26 looking for a cell phone so he is WAY ahead of schedule if it took a year to get the book

 

[tweed]

Shit...............Randy is on month 26 looking for a cell phone so he is WAY ahead of schedule if it took a year to get the book

ROFL!!!

I haven't done the phone thing either. Just about given up on it to tell the truth. I gotta find a phone that I won't have to pay an arm and a leg for and pay for data service on top of that. Would have been pushing 150 bones a month just for cell phone shit if I would have upgraded to a BB. With all the extras hitting me out of nowhere at home this month, I gotta cut back some. Freaking roof and orthodontist bill this month just about put me under.

 

[StevieRaveOn]

That is so incredibly awesome. I would love to take this seminar. I bet that amp sounds awesome too. The seminar is such a great idea. Very, very, very cool!!!!

Shea,
I saw we do like we were all talking about a while back and try to team up for a class... building during the day, hangin in the evenings.

 

[StevieRaveOn]

Steve, thanks a lot for the pics and the write-up, this sounds like a great class Bruce is putting on. What's the ballpark setback for it?

 

[badger71]

Great review Steve. I am looking forwrd to the clips.
Did Bruce mention anything about coming to LA ?

He didn't when I was there. I think the biggest issue is finding a place to hold it that has all the necessary equipment...

Steve

I don't know about any LA locations, but, if Egnater is a NAMM member, they may be able to use the NAMM building in Carlsbad, CA as a starting point. It has classrooms that can be booked by members for seminars, board meetings, etc....I imagine they may be able to work something out with covering the floor and opening the doors for ventilation. Egnater would just have to supply/rent the necessary electronic/soldering equipment. I don't know...its a thought.....

 

[Anonymous]

Steve, thanks a lot for the pics and the write-up, this sounds like a great class Bruce is putting on. What's the ballpark setback for it?

$1600 + travel costs. A steal considering you get a killer amp and all this knowledge! You'd pay $1150 for just the unbuilt kit if you could get one...

Steve

 

[Anonymous]

Great review Steve. I am looking forwrd to the clips.
Did Bruce mention anything about coming to LA ?

He didn't when I was there. I think the biggest issue is finding a place to hold it that has all the necessary equipment...

Steve

I don't know about any LA locations, but, if Egnater is a NAMM member, they may be able to use the NAMM building in Carlsbad, CA as a starting point. It has classrooms that can be booked by members for seminars, board meetings, etc....I imagine they may be able to work something out with covering the floor and opening the doors for ventilation. Egnater would just have to supply/rent the necessary electronic/soldering equipment. I don't know...its a thought.....

Unless Bruce was gonna hold it at another amp builder's place, I don't see how this would be possible. 6 soldering stations, tools for each, o-scope, DMM, VTVM, resistive load box, variac, cab, guitar, appropriate table lighting, cables, heat gun, extra parts when things inevitably get broken, etc... too much stuff to carry around... just doesn't seem practical or worth the effort for Bruce...

Steve

 

[zepman]

Wow Steve, thats looks like a freakin blast!!!!!
I didnt get a chance to read through your whole post(will later) but it looks like the amp you built is based on a JTM45??For a guy who hasnt done much soldiering your work looks GREAT!!(In fact better then most production amps I look at )
Does everybody build the same amp or are there options????
How much does a class like this set you back?........................Thanks for sharing this with us VERY cool ................John

It was an awesome experience, John. You would LOVE it...

The amp is based on a JTM 45 kit, but when you are finished, the amp circuit is much more like a high gain 2204. Bruce designed the circuit himself and it has a TON of gain on tap. Rodded Marshall territory with only 3 gain stages.

It is funny, my soldering wasn't very good at first, but Bruce kinda shows you how to do it right and gives you a few tips and after a few hundred connections, you are an expert. Everyone builds the same amp as that is the only way Bruce can guarantee you are going to end up with a working amp in one day. The class is $1600 (the kit alone would run you $1150 if you could even buy it) and is worth twice that for what you learn and you get a kickass high gain Marshall to boot...

Steve

Thanks Steve,
Once I get my kid graduated and to work I will make this class a TOP priority. Its time I did something for me for a change ...............John

 

[Harvest]

Looks like a blast!

It's interesting that the heater wires aren't twisted together. I'm guessing there's a reason why they're not but I can't really tell from the mass of wires AC heater filaments maybe?