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5/31/2000 10:43 PM
Trace
email
Web Site
Hey all;  
 
I finally got the beginnings of a website up and running (whew) I want to add a tech section that would be a bit different than what Randall and RG (as well as others) have, only because theirs already rocks and I can't improve on theirs!! If anyone has any ideas please email me or post them here.  
 
I also want to include a mess of links so please feel free to send me a bunch of links to some cool sites!!!!  
 
Many thanks!!!!  
Trace  
http://hometown.aol.com/voodooamps/voodooampsindex.html
 
6/1/2000 5:37 AM
Anon
Dear Trace, I love the look of that "Model Z" amp on your page. How many storeys high are those trannies?
 
 
  Tuesday
Book Of The Day The Ultimate Tone, Volume III by Kevin O'Connor
Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

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6/1/2000 12:48 PM
Trace
email
Web Site...MOD PAGE??
quote:
"Dear Trace, I love the look of that "Model Z" amp on your page. How many storeys high are those trannies? "
 
 
Yes, you would need Superman in order to jump over those trannies! (ha, ha) They are pretty massive indeed! That used to be an old Knight mono hi-fi amp. The Output Tranny is actually set up for Ultra Linear and sound pretty amazing to be perfectly honest with you. I'm not the biggest fan of UL OT's but this one sounds really nice. (it's not a plug to sell it either because it's already sold! ha, ha)  
 
TECH PAGE: Should I gear the tech page towards mods or towards newbies? I don't recall as seeing too many sites that have mods by different people, I know Steve Ahola's site has a few.  
 
That might be a cool way to go! We could post mods for some of the most popular Marshall, Fender, Vox, etc. and have many different people add what they would do to to each model so people have a mess of ideas to try. Have everyone here post some mods (or email me some) and I can dedicate a page to just mods. I'd love to actually have more than one page but I'm not sure how much space is avalible. What do you guys think????  
 
 
 
Trace
 
6/1/2000 4:44 PM
Frank Clarke
email

Yes, I'd like to see a collection of other people's amp mods and their experiences of those mods.  
I'd also value your thoughts on the mechanics of working on PCB-based amps, as opposed to PTP.
 
6/1/2000 9:43 PM
Trace
email

quote:
"Yes, I'd like to see a collection of other people's amp mods and their experiences of those mods.  
I'd also value your thoughts on the mechanics of working on PCB-based amps, as opposed to PTP."
 
 
I'm not sure how valuable my opinion is but it's nice to know that someone reads my posts! (ha, ha) I did post under RG's post regarding PTP verses PCB & how many techs say PTP sounds better than PCB's.....I think it's a bit long winded but you can take look at that and see if it makes any sense! (ha, ha)  
 
Marshalls have always been the center of so much "voodoo" and "myth" so I took a very quick stab at trying to unravel the mystery of why PTP Marshalls (or most amps in general) sound better than the PCB versions.  
 
To make a very long story very short...I think many techs over look the importance of a good OT and how it effects the tone overall. You can spend years tweaking a circuit but if the OT is not able to reproduce what you are trying to do then it's pretty pointless in my opinion. The Marshall Plexi's (1987/1959) are the center of so much "voodoo" that people are paying upwards of $3,500.00 to $5,000.00 for an original!!  
 
I'm sure that a great many people will disagree with me and most likely this will ruffle some feathers however, you can build a copy or even take the PCB versions (73-76) and you can make them sound IDENTICAL to the original plexis! I do it all the tine and "yes" changing the OT (or using a plexi-OT if you are building an amp from scratch) is part of  
the difference.  
 
There's also a great deal of mystery surrounding why most 50 watt Marshalls sound so different when compared to their 100 watt big brothers. The circuits are the same but the amps do in fact "sound" different.  
 
I can say with fair certainty that the difference lies within the OT's. The 50 watt OT's are very different in design than the 100 watt OT's and hence the tonal and sonic differences.  
 
I've taken a PCB Super Lead and converted it into a Plexi and then placed them side by side and A/B'ed them with some friends. NO ONE could tell the difference and 80% of the people present were seasoned recording engineers with ears made of gold!  
 
Understanding how OT's work is probably just as difficult & hard to understand as the use of negative/Positive Feedback.  
 
I hope it helps!  
Trace
 
6/1/2000 11:27 PM
Frank Clarke
email

I'd certainly agree to the OT being more significant than the PCB :).  
In the PTP vs PCB thread you said something about working on PCB's being ok whan you got used to it. I was imagining that you might have some handy hints for modding on PCB's. This kind of basic practical information wouldn't be duplicating other websites.  
For example, if I want to try different values for a cathode resistor I might remove the resistor, solder a pin in each hole, and then solder to the pin, so the PCB copper doesn't come loose.  
More extensive modifications start looking really messy (when I do it).  
If I was adding an extra feature to a PCB-based amp, where do I put those extra caps and resistors? I'd like to see some pictures of neatly modded PCB's.
 
6/2/2000 10:09 PM
Trace
email

quote:
"In the PTP vs PCB thread you said something about working on PCB's being ok whan you got used to it. I was imagining that you might have some handy hints for modding on PCB's. This kind of basic practical information wouldn't be duplicating other websites."
 
 
I'm not sure if I have a great hints to be truly honest with you! (ha, ha) What I do is pretty simply really although it's not really the safest way to go. I usually have alligator clips and built some cables so there's a clip on each end.  
 
Then I snip the cap or resistor off from the board. The trick is to snip it as close to the body of the resistor as possible so you have the legs there. Then just bend them up straight and clip the alligator clips to them. This way you can swap out different values verses heating up the PCB so much. the problem is you are working on a live amp! So be very carefull!!!!!  
 
quote:
"For example, if I want to try different values for a cathode resistor I might remove the resistor, solder a pin in each hole, and then solder to the pin, so the PCB copper doesn't come loose."
 
 
What tends to happen is the Pin will get loose because the solder melts on the bottom of the PCB pretty quickly. That's why I use the alligator clips. It works for me but you have to be careful and not get into a rush because that's how you get zapped!!!(ha, ha)  
 
quote:
"More extensive modifications start looking really messy (when I do it).  
If I was adding an extra feature to a PCB-based amp, where do I put those extra caps and resistors? I'd like to see some pictures of neatly modded PCB's."
 
 
I guess it depends on what you would be adding to the PCB as to how/where you would put it. The next time I mod a PCB I'll take some photos. I think there's a Marshall JCM800 ready to go on the bench so I'll email you some photos. Mostly I change out resistor and cap values though.  
 
Trace
 
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