Dave, No, I'd actually like a somewhat restrained volume. I like to play everything from rock to blues to jazz. I need a good clean sound and reasonable distortion and sustain for leads. But it needs to work OK in my living room, too! It sounds like 15-20 watts might do the trick. I need to be able to get enough clean volume; I'm not so worried about the distortion. I really don't have any point of reference. I know my Fender Princeton (solid state) is plenty loud at somewhere around 50 watts? I played a Laney VC15-110 with 15 blazing watts and two EL84's and it was a little light on volume for me. Otherwise, pretty nice. The Vox AC30 was very good. http://www.laney.co.uk/show_prod.php?title=VC15-110 A Champ has never been loud enough for anything but practice, as I recall. I can't imagine performing with it. But the last time I used one was 40 years ago. I haven't any idea at the moment which tubes to use. Nor which output transformer to use; I've found only precious few of these so far. Any reference design you can point me to would be appreciated. If you read my earlier posts, I found a reference design for a Champ-type amp. I might build it first to see what it's like. I've also got an old Gibson GA-9 and should have it working in about a week, as soon as I get the new capacitors and install them. Thanks, Mark Dave King wrote: > One thing about class A's tubes or even a-b's is you don't need anywhere > near the same output that you will with the solid-state versions. 40 watts > will blow people out of their seats in most places. Past that point you > will probably want to just mike the amp. Might need over 100 watts if you > used the solid-state version of the same amp to get the same output. To give > you an idea of what a good tube amp will do I've been building a class a > with > the thumpin output of 3.2 watts!. This is for buddy of mine who plays blues. > Mind you it really depends what you are playing as far as how you > build/tweak > the amp. If your using 5881's I take it you are intending on doing some > crunchy > ear bleeding loud rock? > > He claims it will be enough for any small gigs and it will allow him to > crank > it up to get into distortion without blowing people out of the room. He's > really > anxious to try it out for their next recording session as the Champ they use > gets > too loud at 4.8 watts. I happened to get a pile of nos and milspec tubes > given to > me so we're using those instead of the usual EH/Sovtek stuff. > > Dave > > -----Original Message----- > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf > Of Mark E. Skeels > Sent: December 19, 2006 8:14 AM > To: Microcontroller discussion list - Public. > Subject: Re: [OT] Buikding a tube-based guitar amp > > > Hi, Rich, > > How did they turn out? What config did you use? > > I noticed a lot of tone variation between amps so far and I'm kind of > unsure right now as to what causes that. I've read that bypass caps on > the preamp tubes have a lot to do with this. > > Also, I'm unsure of how big an amp I'd want to make, given the different > configs. All the amps I've played until recently use push pull OP stages > and there 40 to 50 W RMS is enough, but with a class A I'd probably need > more output stage to achieve the same results. > > That seems like a good tip on the DC filament supply, thanks. > > Mark > > Rich wrote: > >> I have built several tube amps. The circuitry is easy . The output >> transformer is an important consideration, A common output tube is 6L6, >> > but > >> I have used 5881. But there are other good tubes. The beam power >> > pentodes > >> have some advantages. Some output transformers will have taps for the >> > screen > >> grids. It is referred to as the Williamson design. I bet you can find a >> > lot > >> of info on the net. If you cannot, let me know and I will see what I can >> come up with. Also, the schematics for Fender, or Gibson or others is >> probably available. If you use DC on the filiments you get rid of some of >> the low hum, especially if you use power transistors in a capacitance >> multiplier configuration. But some people want the hum. It will be >> interesting to see how you progress. >> >> >> >> ----- Original Message ----- >> From: "Mark E. Skeels" >> To: "Microcontroller discussion list - Public." >> Sent: Tuesday, December 19, 2006 9:00 AM >> Subject: Re: [OT] Buikding a tube-based guitar amp >> >> >> >> >>> James, Tony, Dave and Patrick, >>> >>> Many thanks for all of the input. >>> >>> I'll keep you posted; it'll likely be a bit slow moving project because >>> of other commitments. >>> >>> Now does anyone know of any good references on tube guitar amps and >>> audio circuitry? >>> >>> Remarkably, this is one area where tubes do actually seem to produce >>> superior sound. >>> >>> I've been doing some research on the internet. I found out that in >>> addition to their characteristic distortion, which many guitarists >>> prize, it turns out that their response to transient input is can >>> actually sound cleaner and brighter than transistors. They have a softer >>> response to the transient and that tends to smooth out the response and >>> avoids the introduction of clinky sounding even harmonics, or so I read. >>> I would post the link for this, but I lost track of it. It had to do >>> with an audio engineering firm tasked to improve the lousy sound of a >>> large mixing board in a recording studio. Frustrated that nothing was >>> working, they tried a tube preamp and incredibly the harsh sound of the >>> board went away. After a bit of analysis they found it had to do with >>> this initial transient response of the SS preamp in the board vs. the >>> tube preamp. >>> >>> I have verified this by placing a Fender HotRod Deluxe tube amp side by >>> side with an older Fender Princeton Chorus and noted not only the >>> greater richness of the sound but the sparkly quality in the tube amp. >>> Compared side by side, the solid state amp really does sound harsh and >>> grating on the attack. >>> >>> Visiting some local music stores this last couple of weeks I have >>> learned that not all tube amps are this good. For instance, I played >>> some Epiphones that sound really muddy and "blatty." The Vox AC30 (class >>> A) sounded particularly good to me. >>> >>> There are push pull, class a, and class a/b models. all have their >>> unique character. It will take some time to really figure out what I >>> like out of what's available. >>> >>> All of this has led me to become interested in tube guitar amps and to >>> consider experimenting with some of my own designs. The first step will >>> be to learn some more about tubes. It was a subject not broached in my >>> classes at school. >>> >>> I may start here; an open source tube amp design: >>> >>> http://www.torresengineering.com/freplantomak.html >>> >>> This seems to be the premier resource on tube guitar amps: >>> >>> http://www.torresengineering.com/inbydantor.html >>> >>> Mark >>> >>> Dave King wrote: >>> >>> >>>> Mark >>>> >>>> Look around some of the online Amp shops. They will sell you a new old >>>> stock >>>> or reproduction plate for far less than you can do a one off. >>>> >>>> Dave >>>> >>>> -----Original Message----- >>>> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf >>>> Of Mark E. Skeels >>>> Sent: December 18, 2006 7:14 AM >>>> To: Microcontroller discussion list - Public. >>>> Subject: Re: [OT] Restoring vintage Gibson GA-9 guitar amp >>>> >>>> >>>> Actually, I took a little closer look and graphics on the chassis is >>>> just a silk screen. It's not stamped. So I guess unless I can find a new >>>> silk screen, I'm out of luck....... >>>> >>>> Mark >>>> >>>> Mark E. Skeels wrote: >>>> >>>> >>>> >>>>> This old amp has a chrome plated steel control panel that is stamped >>>>> > and > >>>>> then some kind of ink is put into the depressions for letters, graphics >>>>> patterns, etc in the depressions. >>>>> >>>>> Most of the ink is worn away. >>>>> >>>>> Does anyone here know how that is done and what kind of ink to use to >>>>> restore the graphics to the front panel? >>>>> >>>>> Thanks, >>>>> Mark >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>> -- >>>> http://www.piclist.com PIC/SX FAQ & list archive >>>> View/change your membership options at >>>> http://mailman.mit.edu/mailman/listinfo/piclist >>>> >>>> >>>> >>>> >>> -- >>> http://www.piclist.com PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> >>> __________ NOD32 1928 (20061219) Information __________ >>> >>> This message was checked by NOD32 antivirus system. >>> http://www.eset.com >>> >>> >>> >>> >>> -- >>> No virus found in this incoming message. >>> Checked by AVG Free Edition. >>> Version: 7.5.432 / Virus Database: 268.15.24/592 - Release Date: >>> 12/18/2006 1:45 PM >>> >>> >>> >>> __________ NOD32 1928 (20061219) Information __________ >>> >>> This message was checked by NOD32 antivirus system. >>> http://www.eset.com >>> >>> >>> >>> >> > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist