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well at least it's SOMETHING


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6/11/1999 2:09 PM
ken gilbert well at least it's SOMETHING
...which is better than nothing, innit?  
 
 
 
I am sure that all who are responsible for this unique site are working as hard as possible to get it back to its original, exemplary form.  
 
 
 
Meanwhile, I'm throwing diode bounding circuits here and there in the old tube preamp, and--I'll be damned--it sounds good!  
 
 
 
Which reminds me, "it's not what you do, it's how you do it." Location, Location, Location!  
 
 
 
~KG~
 
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6/11/1999 2:55 PM
MBSetzer

Hi Ken:  
 
 
 
Would that be solid-state or tube diodes? Good to hear you are having some luck, of course it's not mainly luck. I say you have to put yourself in position to take advantage of good fortune when it comes along :-)  
 
 
 
One of my favorite scientists, TAEdison said something to the effect that invention is 10 percent inspiration and 90 percent perspiration. If nothing else it applies to you when you load out the BAGA ;-) Your recent schematics were interesting and inspirational. I'll be getting one of the KT90's pretty soon and compare to the KT100 and others like 6550's. IIRC you were using the Ei tubes? With just a small computer fan I have had the KT100 dissipating 60W comfortably at 600V and another rig worked with a NOS GE 6550A dissipating 65W at 450V, it appears they exceed ratings by a good margin, haven't figured out what the life expectancy would be though. This is not exactly non-destructive testing, but that's the purpose of my lab to begin with . . .  
 
 
 
A lot of Ampage fans are wondering what type of remodeling is underway? Maybe Tboy will issue a news flash, hope it's not a virus problem!  
 
 
 
Best Regards,  
 
Mike
 
6/12/1999 7:01 AM
ken gilbert
Mike said:  
 
 
 
Would that be solid-state or tube diodes?  
 
 
 
I said:  
 
 
 
Sahhhlid state, mate. Regular plane-jane LED's. I just kept moving the node at which I shunted to ground through the back-to-back diodes, with no series compliance. It gave me a pretty good understanding of which stages in particular were doing what in terms of distortion. Placing the LED's early on (after 2nd stage of 9 on the distorted channel--in the entire box) didn't lose much (if any) of the "tube sound." It changed it, but it certainly didn't wipe it out. I think it actually tightened things up a bit. Some of my signal voltages get a little erm--shall we say--rambunctious at times, and this simple clamping action prevented too much loss of control.  
 
 
 
That's a great song too... "Loss of Control," by Van Halen, off of Women & Children First, 1st song, side B.  
 
 
 
MOne of my favorite scientists, TAEdison said something to Mthe effect that invention is 10 percent inspiration and 90 Mpercent perspiration. If nothing else it applies to you Mwhen you load out the BAGA ;-)  
 
 
 
KDude, I just got back from a gig, as I speak, as a matter Kof fact. It was in Newport, RI, mostly punk venue, at Kleast tonight. I brought the minimum rig I could feel Kcomfortable with. It ended up being 125 + 130 + 40 + 15, Kor over 300 pounds worth of shit. I need to make a 600W Kamp that weighs 10 pounds instead of 100... Then I'll Kretire.  
 
 
 
MYour recent schematics were interesting and inspirational. MI'll be getting one of the KT90's pretty soon and compare Mto the KT100 and others like 6550's. IIRC you were using Mthe Ei tubes? With just a small computer fan I have had Mthe KT100 dissipating 60W comfortably at 600V and another Mrig worked with a NOS GE 6550A dissipating 65W at 450V, it Mappears they exceed ratings by a good margin, haven't Mfigured out what the life expectancy would be though. This Mis not exactly non-destructive testing, but that's the Mpurpose of my lab to begin with . . .  
 
 
 
My thoughts exactly. The KT100 is supposed to have comparable electrical capabilities to the KT100, only made in Asia (China, I think). It is good to hear of that kind of performance, since Yugoslavia isn't quite back on the map yet.  
 
 
 
I've since switched to U/L mode into 4X the impedance (switching from parallel to series on the speakers). The sound is more focused, and tighter, and I KNOW the tubes are a little happier. Not nearly the same amount of heat coming off of those puppies. The tone had certainly changed, but I got around that by some knob twists upstream. At least I got it to something I could play with.  
 
 
 
I'm beginning to realize it isn't so much as attaining a destination, it's merely the pursuit of it, never to quite get there.  
 
 
 
 
6/12/1999 3:46 PM
Lee

Did you have to do any "tuning" of other components in the cicuit? I tried a diode bounding circuit copied from O'Connor's book in a Traynor and it was really buzzy. Kevin said that's why tuning is required but I didn't feel like fiddling any more so I took it out.  
 
 
 
Lee
 
6/12/1999 7:36 PM
ken gilbert
Actually I didn't do any tuning other than careful placement of the point of bounding. It is also important to note that the diodes used were red LED's, which, according to some info found on Jack Orman's web site, tend to have ahigher percentage of even harmonic distortion than other signal, or rectifying diodes.  
 
 
 
The node which is bound is right before a low-current tube stage, which used to clip the signal quite heavily anyway, so it didn't really alter the tone that much. I suspect that if you tried this on a normally very clean channel you might not like the result.  
 
 
 
~KG~
 

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