mods for son of ampzilla & sae 2400L

schematic of Tigersaurious
 

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burnedfingers said:
schematic of Tigersaurious
This is great, Thanks.

By curiousity is going now. When was this amp made, any idea how many?

It's hard not to notice the series (cascoded) output stage. Probably for the same reason Mr B used it. A completely opposite approach to the Ampzilla.

What is the output power, the supply voltages (the image on my monitor isn't quite clear enough). Is there any kind of technical description? Anything like the Audio Amatuer or Audio articles on the Ampzilla?

If your interested in more details on the Ampzilla I have a pretty good collection.

Could I trouble you to take a picture of just the upper part of the voltage amp/ output stage? When you have time. Alot of the component values are difficult to read.

I' still haven't gotten a reply from my friend, but like me he has a pretty full life that comes before the fun stuff. I might get a chance to give him a call over the weekend.

Regards, Mike.
 
MikeBettinger,

I will email you some readable scans of the schematic plus pictures of the amplifiers.

I dug out my copy of the 121G schematic and it looks like the changes from the prior circuit were all in the DC Servo circuit.
My board has had these changes made to it. I believe death was caused by tantalum cap failure/fire/ = death to board.
 
burnedfingers said:
MikeBettinger,

I will email you some readable scans of the schematic plus pictures of the amplifiers.

I dug out my copy of the 121G schematic and it looks like the changes from the prior circuit were all in the DC Servo circuit.
My board has had these changes made to it. I believe death was caused by tantalum cap failure/fire/ = death to board.


Thanks, something new to dig into! Although I'm going to be tied for the better part of the weekend and won't get much of a chance to examine them. It will give me something to look forward to.

The 121G was the version where GAS actually got the AmpzillaII stable. They designated it the Ampzilla IIa Both the 121E and F were time bombs and didn't like looking into much more than a load resistor on the bench.

In my humble opinion the 121B and the 121G are sonically and stability wise the best versions.

Do you have the schematic for the E or F? I should have one in my files if you want to compare them. Off hand I forget what all the changes were.

I'll get back later in the weekend.

Thanks again, Mike.
 
In my humble opinion the 121B and the 121G are sonically and stability wise the best versions.

I would have to agree. I've probably done more with the 121B myself. Sonically they are sweet.
Do you have the schematic for the E or F? I should have one in my files if you want to compare them. Off hand I forget what all the changes were.

I don't have a good copy of the "E".

I sent you an email from the board here. Unfortunately I cannot send files with the email. If you care to send your email address I will send the files and pictures.

Thanks,
Joe
 
I could use some info on the Gas 100A IC that was used in the newer Ampzilla's. I believe it was the Motorola MPQ6002 which is no longer made. Is there a solution?

I can remember quite a high failure rate as a result of the bias IC not contacting the heat sink. If my memory is correct it took a shim of around .025 to obtain contact with the heat sink and therefore track the output stage correctly. James B. however was blameless as usual and made the claim that there was a shim installed in every Ampzilla. Funny, I never saw any in the amplifiers that I serviced but when they left me they had them.

There were a lot of butchershops out there that attempted to service the "GAS" line unfortunately and many died by technician so to speak.

One shop stood out over the years as being able to do reliable rebuilds and modifications and that was "Gasworks" I've had the chance to see the work they did on several pieces of equipment and it was flawless.
 
burnedfingers said:
I could use some info on the Gas 100A IC that was used in the newer Ampzilla's. I believe it was the Motorola MPQ6002 which is no longer made. Is there a solution?

I have a drawer full of them if you need any. Basically, as you probably already know, it's a NPN/PNP quad transistor array. You can substitute matched transistors but the trick is coupling them to the heatsink.


One shop stood out over the years as being able to do reliable rebuilds and modifications and that was "Gasworks" I've had the chance to see the work they did on several pieces of equipment and it was flawless. [/B]


Fat chance.

I wouldn't expect anyone to understand what Gasworks was doing; especially one looking at it trying to fixing it; considering it didn't follow the schematic anymore. I doubt anyone would look at my work as flawless! What I do find interesting is that so many survived for more than twenty years only to be called bad now...

Sonically what it did was more the point. I did an amazing business based on that. Too bad I wasn't a business man.

I was just curious about the Tigersaurus. I don't understand the attempt to blow smoke up my arss. The past is the past and I'm just looking to pass the time.

Mike.
 
What I do find interesting is that so many survived for more than twenty years only to be called bad now...

Who called them bad? I didn't

There were a lot of shops out there that claimed to be able to repair the Ampzilla correctly and they didn't do a good job. There were some reasons for this which included the wrong transistors and sloppy workmanship.
I don't understand the attempt to blow smoke up my arss.
I only attampted to give credit where credit was due.

Please accept my apology.
 
Originally posted by burnedfingers Who called them bad? I didn't

To have worked on them and call them flawless is a bit of a stretch, this was 20 years ago. I was pulling out current sources, resequencing grounds and supply routing; All based on squeezing resolution out of the designs. It was heretical back then and accepted even less now. I had enough "experts" put the work down that I find it hard to believe the concept of anyone getting it, muchless calling it flawless.

I went ten rounds with Mr B (a few years back on the SAE_talk forum) over whether or not I was an Idiot and how Gasworks ruined his perfect designs.. I defended myself well enough that he backed down after too long a time. I'm not opening the door again.

Discussing Gasworks, especially on this site, would be pretty much asking for a good beating, It was all based on endless 24/7 experimenting on anything and everything and applying the best to whoever/whatever had heard my work and agreed to what I was suggesting. Not a simulation in sight.


Please accept my apology. [/B]


No need to apologize, this is me. I probably should but the concept that anything good came out of that 15 years of my life stretches reality for me. It sucks how jaded we get as we get old, and I'm not even old.

Mike.
 
Could someone point me towards a 121E schematic? I have a F version but from what I can see it isn't even close.

I have tried several zip formats so that I could post the tigersarous schematic but everything seems to fail. Is there someone I could email it to that could put it on the board with enough detail that you can actually make it out?

MikeBettinger,

Would you send me an email? Maybe I could send you the schematic and photos directly.
 
burnedfingers said:
If we could talk TomWaits (Shawn) into buying an Ampzilla II I'm sure he could make some nice new driver boards.

Are you up to the task Shawn? I'll trade you a DC 300 for a pair of Ampzilla driver boards...:clown:

Can you show me close up shots of the top and bottom of the board you want to clone?

DC300...hmm I already have a few of those but one more could be nice. ;)

Cheers,

Shawn.
 
Art,

Thanks for the reply. It would be great if you could email me a 121G schematic. I have the "F" but not the "E". My boards are the "E" version with a bunch of tack ons. I just found my MPQ tech sheet.

Shawn,

I'm trying to find a good board that I could take the parts off of and send you. I can take care of the drilling.

Both boards are damaged and only one is workable. The other you can stick your little finger thru the hole in the board.

MikeBettinger,

You will find that sometimes we can get into heated arguements here on this forum and that the moderators tend to straighten us up quickly. I don't think you are going to find the hero worship that you found on the other board. I also went a couple of rounds with you know who. Thats past history and we should move on. I personally welcome your experience and knowledge and would like to selfishly gain from it.:D I would be more than happy to purchase some parts or boards that you might wish to sell. I would like to get my Ampzilla II up and running again and put it up against the pair of 250 watt Tigersarous amplifiers I have. In addition to listening to them for any differences I would also like to check them for IMD and THD and see how they fair. It would be interesting to break down the circuits and discuss the difference between them as well as the problems. This could end up to be a very interesting learning experience.

I sent you an email and maybe it didn't find its way to you. As I pointed out earlier I am more than willing to pay for any parts that you might be willing to sell. If you would be interested in helping it would be much appreciated.

Thanks,
Joe
 
burnedfingers said:


I sent you an email and maybe it didn't find its way to you. As I pointed out earlier I am more than willing to pay for any parts that you might be willing to sell. If you would be interested in helping it would be much appreciated.

Thanks,
Joe

Joe,

I have not read your e-mail as of yet. I'll read it later and respond. I would very much like to learn more about the Tigersaurus.

I feel like I should and do appologize for my quick temper, but the reasons for it are not unfounded, but have absolutely nothing to do with you.

They stem from an incident 6-7 years ago where a bit of sucking up by an old customer took a nasty turn. I felt compelled to respond to the SAE site nonsense when Gasworks bashing became part of the weekly agenda. Im learning not to try to discuss anything outside of the textbooks on this site and have been happy just taking it in.

My main curiosity is the Tigersaurus and am quite happy to pass on anything I have on the Gas gear; I'm not looking for money, just something interesting to do.

As far as laying out an ampzilla PCB, I'd suggest building the 121G boards based on the schematic. The form factor is the same for all. I've toyed with the idea myself over the years, except Amp no longer makes the connectors.

I still have no info on the board availibility. I spoke with my friend and he was going to dig around and get back to me.

Mike.
 
bielawa said:
QUESTION .I HAVE AMPZILLA AND NEED TRANSISTORS MARKED
GAS108 AND GAS107 ,WHAT CAN I USE INSTEAD?

Original Parts

GAS107 original MPSU07. For diff amps use 2SC2240 or 2N5551, for Vas 2SC2682

GAS108 original MPSU57. For diff amps use 2SA970 or 2n5401, for Vas 2SA1142

Obviously the pinouts are different and on the Vas suggestion the leads are thicker.

Mike
 
Must be the version one of the Ampzilla. I couldn't remember the PN's. I have a 100 or so of the 5401's and 5551's and 5550's if you need some. I never used the 970's and 2240's but they would be an excellent choice. TOA, Altec, EV, and other commercial amplifier manufacturers used them without a problem.
At any rate get the old MPS U07's and 57's out of there. The same go for the "Son" of Ampzilla. This also goes for any MPS U10's and U60's or U06's and 56's. They were a good transistor in their day but not all that suited for diff service in my opinion.