Hi everyone, long time reader first time poster 😉
I'm looking at doing my first build and was considering an Alessandro beagle style amp. 2 x el84 power section, 6SL7 octal preamp, full tone stack, running in true class A and I believe ultra linear as well (I believe most of George's amps are ultra linear?)
Does anyone know of similar build to this with good documentation / layouts? The Beagle looks like a relatively simple build, I'm just not sure about speccing the correct transformers etc.
Any help would be greatly appreciated!
Rick
Alessandro Beagle Style build
Moderators: pompeiisneaks, Colossal
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Stevem
- Posts: 4625
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Alessandro Beagle Style build
Since you are interested in a octal tube preamp section you may want to check out a build of 2008 vintage from boozhound labs.
It's a 15 watt amp making use of a 6SL7, a 6SN7 and two 6v6s for outputs and a 5Y3 recto that could be subbed to EL84s with ease!
The build uses a cool transformer biased cathode on the PI tube,and offers a nice advantage over just the normal resistor set up of a long tailed PI!
I built this amp over the winter and I truly love it!
I just did a web search for the schematic and could no longer bring it up, but if you email him at jsn@boozhoundlabs.com I would guess he could provide you with the info, if not let me know and I can fax you or may be email you a copy.
By the way I do not see the need for, or like the use of a UL output stage for guitar , Bass is quite a different story though!
This is also the reason why the silver face master volume era of fender amps sounded like such crap unless you needed pristine clean sounds that where sterile and stiff!
It's a 15 watt amp making use of a 6SL7, a 6SN7 and two 6v6s for outputs and a 5Y3 recto that could be subbed to EL84s with ease!
The build uses a cool transformer biased cathode on the PI tube,and offers a nice advantage over just the normal resistor set up of a long tailed PI!
I built this amp over the winter and I truly love it!
I just did a web search for the schematic and could no longer bring it up, but if you email him at jsn@boozhoundlabs.com I would guess he could provide you with the info, if not let me know and I can fax you or may be email you a copy.
By the way I do not see the need for, or like the use of a UL output stage for guitar , Bass is quite a different story though!
This is also the reason why the silver face master volume era of fender amps sounded like such crap unless you needed pristine clean sounds that where sterile and stiff!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Alessandro Beagle Style build
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:34 am, edited 1 time in total.
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Stevem
- Posts: 4625
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Alessandro Beagle Style build
The choke is a easy to get ( at least in the US) Hammod 157G.
It's a 30h 40 madc 595 ohm choke.
Oh! And I added the much in my mind needed 470 ohm screen resistors to the build.
It's a 30h 40 madc 595 ohm choke.
Oh! And I added the much in my mind needed 470 ohm screen resistors to the build.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Alessandro Beagle Style build
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:41 am, edited 1 time in total.
Re: Alessandro Beagle Style build
The transformers are made by Magnequest. If you contact Mike there, he may sell a similar transformer to you. I had a beagle for many years. Very nice amp but cannot come close to the 15 watt Rockets that I have built.
Re: Alessandro Beagle Style build
If you don't mind a bit of silicon, the choke could be replaced by a CCS on the cathode, some other changes may also need to be made, but I do not think a guitar amp would benefit much from either, seems a bit of an overkill... 
Re: Alessandro Beagle Style build
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:45 am, edited 1 time in total.
Re: Alessandro Beagle Style build
The CCS when not overdrive is "too balanced" and when overdriven all he11 breaks loose, that's why it's not really suitable for a guitar amp... I suggested it as an alternative to the choke, because it costs just pennies compared to a choke.matt h wrote:I wanna say Merlin wrote about CCS in the LTPI chapter and pretty much said they sound awful when overdriven. I'd definitely be interested to hear other people's experiments in this realm--either with chokes for PI bias resistors, or with silicon for a CCS
Re: Alessandro Beagle Style build
Thanks for all the info guys! Plenty of food for though there!
Loctal, that 15 watt rocket build sounds very interesting! Do you have any sound clips of it?
Loctal, that 15 watt rocket build sounds very interesting! Do you have any sound clips of it?