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Alessandro Beagle in new GP Magazine


 
12/23/1999 10:30 PM
Mitch Alessandro Beagle in new GP Magazine
Has anybody seen the review in the new GP of the Alessandro Beagle amp? It has pictures of the inside of the chassis with the article. Looks like a 6SL7 preamp with a Fender type tone stack right after the first stage. A second 6SL7 is used for the LTP-PI to drive a pair of UL, cathode-biased Sovtek EL84's in Class A at 240V. The article says the output tubes for all the Alessandro amps are run in UL. The pictures are color so I was hoping to make out some of the values used on the resistors. It looks to me like 220k plate loads on the 1st 6SL7 and a 470 bias resistor on the PI. All the caps in the PI (except the input cap) are paper-in-oil and look to be the same size; I would guess 0.1 microfarad. The PI input cap and two of the caps in the tone stack look to be orange drops; they look like the 0.02 microfarad size and shape to me. I would love to hear your opinions on what all the values for the resistors and caps might be for this supposedly great sounding amplifier, as I was thinking of building something very similar but with 6V6 output tubes instead of the EL84's. Thanks.
 
12/24/1999 5:56 PM
Scott Swartz
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I have built a 2 6L6 UL amp with ZNFB and I used .068 caps in the PI to tighten the bass. With no feedback to reduce the damping factor I find that I get a better sound with smaller caps. Everything is interactive so just sub in different parts and see how it sounds. UL amps have a very smooth distortion that works well for blues, etc.  
 
All those high priced parts used in the Beagle may or may not sound better for guitar amps. For instance, the Elna or Black Gate electrolytics. I use Solen caps in my hifi designs, but I prefer the graininess and compression of Sprague electrolytics in guitar amps.  
 
If I were going to purchase a UL amp, the Dr. Z Route 66 certainly looks like a better value.  
 
 
 
 
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12/24/1999 7:44 PM
Patrick
The first thing I noticed about the layout is that it appears he has broken one of what I thought was a cardinal rule, that being the position of the PT and OPT. Both are positioned so the laminations are parallel. On all my DIY's I've always placed them at 45 degree angles, even when they are seperated by the length of the chassis. Even his choke is parallel. How does he get away with this? The article didn't say (unless I missed it) but the pots appear to be CTS, not sure though.
 
12/25/1999 3:26 AM
MKB
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Just got the magazine today and saw something strange (to me); perfboard and flea clips? I haven't seen this construction method in any amp so far. I would think the flea clip would not give a very good support for large components like the large capacitors in this circuit. I am not being critical as much as curious. Has anyone else here used this technique?  
 
Also, has anyone here heard the Beagle? It has two EL84's class A ultralinear. According to Dr.Z, the EL84 doesn't sound so good in an ultralinear stage, however the article certainly praises the use thereof in the Beagle.
 
12/25/1999 11:25 PM
BWilliamson
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quote:
"something strange (to me); perfboard and flea clips? I haven't seen this construction method in any amp so far."
 
 
As I've been informed, K.Fischer also builds his amps in this manner for fast tweaking of components. Since Allesandro is one of K.F.'s previous students it doesn't surprise me.
 
12/27/1999 1:18 AM
DavidB
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I,m new to this,uh what is a flea clip?
 
12/30/1999 12:39 AM
Bob C.
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Like a roach clip only smaller ;)
 
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