guitar amp DIY ?
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vibrolax
Well-known member
fum,
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon
AnalogPackrat
Well-known member
[quote author="vibrolax"]
That pentode thing won't be my last project in that vein. While triode outputs probably are good for mellowing the buzziness from heavy preamp distortion, I greatly prefer the brightness of pentodes for clean to crunchy sounds.
The Pultec happened because I picked up a decent mic-to-grid transformer at a hamfest last year, and decided to build a project around it. I just turned the prototype rig I built first into a high impedance instrument input preamp by replacing the input transformer with a capacitor. Very promising so far.
-Jon[/quote]
Interesting. I see you play a Les Paul. I'm more of a Telecaster (copy w/Duncans) and Rickenbacker (w/toaster tops) kinda guy myself. I wonder how the all pentode design would work with the tamer single coils. Ever tried?
Well, if the Pultec is easy to switch to a nice DI that makes it even more tempting. Keep us informed and thanks again for the cool page.
Analog Packrat
That pentode thing won't be my last project in that vein. While triode outputs probably are good for mellowing the buzziness from heavy preamp distortion, I greatly prefer the brightness of pentodes for clean to crunchy sounds.
The Pultec happened because I picked up a decent mic-to-grid transformer at a hamfest last year, and decided to build a project around it. I just turned the prototype rig I built first into a high impedance instrument input preamp by replacing the input transformer with a capacitor. Very promising so far.
-Jon[/quote]
Interesting. I see you play a Les Paul. I'm more of a Telecaster (copy w/Duncans) and Rickenbacker (w/toaster tops) kinda guy myself. I wonder how the all pentode design would work with the tamer single coils. Ever tried?
Well, if the Pultec is easy to switch to a nice DI that makes it even more tempting. Keep us informed and thanks again for the cool page.
Analog Packrat
http://www.emerysound.com/Superbaby.html
this is the amp I was thinking about earlier. Having something around the studio like this would be incredibly useful. Any ideas as to what could be happening in that circuit- how can you accomodate that many different tube types in a plug and play, single ended environment- is this normal for cathode biased designs? Can anyone comment on that?
building something with that kind of flexability would be way cool.
dave
this is the amp I was thinking about earlier. Having something around the studio like this would be incredibly useful. Any ideas as to what could be happening in that circuit- how can you accomodate that many different tube types in a plug and play, single ended environment- is this normal for cathode biased designs? Can anyone comment on that?
building something with that kind of flexability would be way cool.
dave
vibrolax
Well-known member
[quote author="AnalogPackrat"]
Interesting. I see you play a Les Paul. I'm more of a Telecaster (copy w/Duncans) and Rickenbacker (w/toaster tops) kinda guy myself. I wonder how the all pentode design would work with the tamer single coils. Ever tried?
Well, if the Pultec is easy to switch to a nice DI that makes it even more tempting. Keep us informed and thanks again for the cool page.
Analog Packrat[/quote]
In *that* picture I'm playing a Les Paul, but I also play a Strat. In March I replaced the LP's pickups with a set of Bill Lawrence L-450 humbuckers with a coil split wired to a pull switch in the tone pots. Now the LP makes very nice single coil sounds. It's an entirely different animal, with plenty of twang and cut.
There is less crunch in single coil mode, but not that much less. The preamp pentode is running at the lower end of its possible gain range. A different plate, cathode, and screen resistor (and more voltage) would get more gain. With no tone stack and driving the sensitive 6AK6, it has about all the crunch I usually need. To get really saturated leads, gotta use a pedal, though. It's pretty much the same story with the strat.
The Pultec-as-DI is easy. I'm working out the best way to switch the input end between mic transformer and instrument. I'll update the project when I finish.
-Jon
Interesting. I see you play a Les Paul. I'm more of a Telecaster (copy w/Duncans) and Rickenbacker (w/toaster tops) kinda guy myself. I wonder how the all pentode design would work with the tamer single coils. Ever tried?
Well, if the Pultec is easy to switch to a nice DI that makes it even more tempting. Keep us informed and thanks again for the cool page.
Analog Packrat[/quote]
In *that* picture I'm playing a Les Paul, but I also play a Strat. In March I replaced the LP's pickups with a set of Bill Lawrence L-450 humbuckers with a coil split wired to a pull switch in the tone pots. Now the LP makes very nice single coil sounds. It's an entirely different animal, with plenty of twang and cut.
There is less crunch in single coil mode, but not that much less. The preamp pentode is running at the lower end of its possible gain range. A different plate, cathode, and screen resistor (and more voltage) would get more gain. With no tone stack and driving the sensitive 6AK6, it has about all the crunch I usually need. To get really saturated leads, gotta use a pedal, though. It's pretty much the same story with the strat.
The Pultec-as-DI is easy. I'm working out the best way to switch the input end between mic transformer and instrument. I'll update the project when I finish.
-Jon
vibrolax
Well-known member
[quote author="soundguy"]http://www.emerysound.com/Superbaby.html
this is the amp I was thinking about earlier. Having something around the studio like this would be incredibly useful. Any ideas as to what could be happening in that circuit- how can you accomodate that many different tube types in a plug and play, single ended environment- is this normal for cathode biased designs? Can anyone comment on that?
building something with that kind of flexability would be way cool.
dave[/quote]
I don't know what's inside the superbaby, but quite a bit of tubular plug and play flexibility can be accomplished with just a good choice of B+ and cathode resistor. Other commercial products in this vein include the THD Univalve, and Groove Tube electronics Soul-o-single http://www.groovetubes.com/product.cfm?Product_ID=1661.
I think some of these might also include a switch for high-and-low B+ voltage.
-Jon
this is the amp I was thinking about earlier. Having something around the studio like this would be incredibly useful. Any ideas as to what could be happening in that circuit- how can you accomodate that many different tube types in a plug and play, single ended environment- is this normal for cathode biased designs? Can anyone comment on that?
building something with that kind of flexability would be way cool.
dave[/quote]
I don't know what's inside the superbaby, but quite a bit of tubular plug and play flexibility can be accomplished with just a good choice of B+ and cathode resistor. Other commercial products in this vein include the THD Univalve, and Groove Tube electronics Soul-o-single http://www.groovetubes.com/product.cfm?Product_ID=1661.
I think some of these might also include a switch for high-and-low B+ voltage.
-Jon
the superbaby has a hi and low power switch.
Is there a good link where I can read up a bit more about theory in regards to cathode bias single ended amps? I sorta get it but not nearly enough to think clearly about it.
dave
Is there a good link where I can read up a bit more about theory in regards to cathode bias single ended amps? I sorta get it but not nearly enough to think clearly about it.
dave
Flatpicker
Well-known member
[quote author="vibrolax"]I take it you've seen Doug Hoffman's version of a simplified AC-30 TB?...[/quote]No, I haven't seen that yet. Thanks for the link! How about this circuit with Mercury Magnetics transformers and Weber speakers? Might just kick the butt off anything out there. :green:
Flatpicker
Well-known member
[quote author="soundguy"]...feel bad for your neighbors, haha...[/quote]Yep. I'm going to need a power soak or something. Anyone DIY'd one of these?
vibrolax
Well-known member
[quote author="soundguy"]the superbaby has a hi and low power switch.
Is there a good link where I can read up a bit more about theory in regards to cathode bias single ended amps? I sorta get it but not nearly enough to think clearly about it.
dave[/quote]
Here's a write-up for beginners, by a former beginner. I used it to start understanding loadlines (for triodes, or triode-strapped pentodes) a few years ago. I bet it will push you in the right direction
http://www.boozhoundlabs.com/howto/
-Jon
Is there a good link where I can read up a bit more about theory in regards to cathode bias single ended amps? I sorta get it but not nearly enough to think clearly about it.
dave[/quote]
Here's a write-up for beginners, by a former beginner. I used it to start understanding loadlines (for triodes, or triode-strapped pentodes) a few years ago. I bet it will push you in the right direction
http://www.boozhoundlabs.com/howto/
-Jon
this is kind of a thing of beauty.
you pay for it though... www.carramps.com
solen power filters, thats something to try next time for sure.
this also looks way interesting-
http://www.electrosonicamplifiers.com/neptune.htm
offers two different output stages, dont see that everyday...
this is a pretty good read also-
http://www.sheldonamps.com/amptalk.htm
dave
you pay for it though... www.carramps.com
solen power filters, thats something to try next time for sure.
this also looks way interesting-
http://www.electrosonicamplifiers.com/neptune.htm
offers two different output stages, dont see that everyday...
this is a pretty good read also-
http://www.sheldonamps.com/amptalk.htm
dave
[quote author="vibrolax"]fum,
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon[/quote]
At present, yes. Again, this is just some spare metal I had around, that I started mounting things in.
First foray into guitar amps. Input jack on the same side as output transformer is bad :?:
[quote author="soundguy"]
Is that orange inspired?
feel bad for your neighbors, haha
[/quote]
this is very orange inspired. You're lookin at a complete tranformer set from Matamp, and will end up being a 120W of pure tube get the policemen next doors attention :wink:
The prototype is for a friend who plays in a loud ass rock band, and can easily make use of this.
The next one will be an 80W version for the studio =)
ju
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon[/quote]
At present, yes. Again, this is just some spare metal I had around, that I started mounting things in.
First foray into guitar amps. Input jack on the same side as output transformer is bad :?:
[quote author="soundguy"]
Is that orange inspired?
feel bad for your neighbors, haha
[/quote]
this is very orange inspired. You're lookin at a complete tranformer set from Matamp, and will end up being a 120W of pure tube get the policemen next doors attention :wink:
The prototype is for a friend who plays in a loud ass rock band, and can easily make use of this.
The next one will be an 80W version for the studio =)
ju
If you're looking for something low power and kinda crunchy, try a 12ax7 pre into a 6sn7 driving a 300b. It wont do more than 15-20 watts but will definitly give some power amp crunch. I build this as a project a few years ago, it definatly has a unique sound as a guitar amp. esp. into a mashal stack
the 300b is a very linear tube but when pushed it gets a little upset, just enough to sound awsome.
also if you google '300b schematic' there are a bunch out there most (all? and who wouldn't run a 300b single ended?) of which are SE and cathode biased
cathode biasing, like other kinds of biasing, works to make the control grid of the tube negative with respect to the cathode. when a tube is idle current flows through the tube from the anode to the cathode and then through a resistor to ground. if this current is, say 1ma, (about what a 12ax7 would draw) and there is a 15k resistor connecting the cathode to ground there will be a 15 volt difference between the cathode and the ground. ie the cathode will be 15 volts above ground.
In most situations you will notice a 1M resistor connecting the grid directly to ground. this is very little loss for audio signals. It also holds the grid at approximatly the same voltage as the ground because there is little or no current through the 1M resistor and there for no voltage drop. because the grid is at '0' volts and the cathode is at '+15' we can see that this will give us a grid 15 volts belowthe cathode.
if you want a better explanation try reading over this site:
http://www.dogstar.dantimax.dk/tubestuf/mchowit.htm
it is a simple vacuum tube preamp with almost every component explained in detail.
the big difference between these preamps and most other output stages is that the ouput stages are transformer coupled.
good luck!!
(ps I think radio shack makes a cheap 8 ohm 10 watt non inductive resistor... power soak idea?
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=271-120
maybe a crap load of those and an output transformer wired backwards or something...)
the 300b is a very linear tube but when pushed it gets a little upset, just enough to sound awsome.
also if you google '300b schematic' there are a bunch out there most (all? and who wouldn't run a 300b single ended?) of which are SE and cathode biased
cathode biasing, like other kinds of biasing, works to make the control grid of the tube negative with respect to the cathode. when a tube is idle current flows through the tube from the anode to the cathode and then through a resistor to ground. if this current is, say 1ma, (about what a 12ax7 would draw) and there is a 15k resistor connecting the cathode to ground there will be a 15 volt difference between the cathode and the ground. ie the cathode will be 15 volts above ground.
In most situations you will notice a 1M resistor connecting the grid directly to ground. this is very little loss for audio signals. It also holds the grid at approximatly the same voltage as the ground because there is little or no current through the 1M resistor and there for no voltage drop. because the grid is at '0' volts and the cathode is at '+15' we can see that this will give us a grid 15 volts belowthe cathode.
if you want a better explanation try reading over this site:
http://www.dogstar.dantimax.dk/tubestuf/mchowit.htm
it is a simple vacuum tube preamp with almost every component explained in detail.
the big difference between these preamps and most other output stages is that the ouput stages are transformer coupled.
good luck!!
(ps I think radio shack makes a cheap 8 ohm 10 watt non inductive resistor... power soak idea?
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=271-120
maybe a crap load of those and an output transformer wired backwards or something...)
vibrolax
Well-known member
[quote author="soundguy"]this is kind of a thing of beauty.
dave[/quote]
Here are some Univalve gut pics:
http://www.acplink.com/chassis/display.aspx?curpage=48
That site has a wide assortment of amp anatomy on display.
I prefer the turret board aesthetic to the point-to-point or PCB.
Here's another boutique builder with a swappable output tube thing:
http://www.vintone.com/simplex.html
-Jon
dave[/quote]
Here are some Univalve gut pics:
http://www.acplink.com/chassis/display.aspx?curpage=48
That site has a wide assortment of amp anatomy on display.
I prefer the turret board aesthetic to the point-to-point or PCB.
Here's another boutique builder with a swappable output tube thing:
http://www.vintone.com/simplex.html
-Jon
input jack on same side as output transformer...
eck
the input signal from the guitar is very weak. pretend and old lady talking from the other side of the room. now your job is to listen and tell everything you hear to somone else to repeats it loudly. now if this person is right next to you while you are trying to listen.... feed back
if you turn up the gain alot you might get noise from the high power output stuff being picked up and amplified on the wireing from the preamp because they are so close
when designing these, dont forget signal flow, have the most sensitive and weak signals isolated and far from the powersupply and output and as the signal grows, move it closer and closer to the output stages.
also is that the power supply stuff right next to the preamp
i might just be to much of a tube head for this. its not hifi, its guitar....
(you might also think about mounting the power transformer and the output transformer with the iron at an angle to reduce direct magnetic fields... but that is getting a little nerotic...)
I'm sure this baby will live and rock but just be aware, :thumb:
eck
the input signal from the guitar is very weak. pretend and old lady talking from the other side of the room. now your job is to listen and tell everything you hear to somone else to repeats it loudly. now if this person is right next to you while you are trying to listen.... feed back
if you turn up the gain alot you might get noise from the high power output stuff being picked up and amplified on the wireing from the preamp because they are so close
when designing these, dont forget signal flow, have the most sensitive and weak signals isolated and far from the powersupply and output and as the signal grows, move it closer and closer to the output stages.
also is that the power supply stuff right next to the preamp
i might just be to much of a tube head for this. its not hifi, its guitar....
(you might also think about mounting the power transformer and the output transformer with the iron at an angle to reduce direct magnetic fields... but that is getting a little nerotic...)
I'm sure this baby will live and rock but just be aware, :thumb:
vibrolax
Well-known member
[quote author="fum"][quote author="vibrolax"]fum,
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon[/quote]
At present, yes. Again, this is just some spare metal I had around, that I started mounting things in.
First foray into guitar amps. Input jack on the same side as output transformer is bad :?:
ju[/quote]
Yes, putting any of your input circuit near the power supply, or the output transformer and its leads can be problematic.
Marshall and Fender puts the iron on the opposite ends from the preamp. Hiwatt put the OT and PT on opposite sides of the amp, with the OT on the preamp end. But the depth of the box (and very careful layout) allowed them to get away with it.
-Jon
That's a very compact layout for what looks like something insanely powerful, judging from the 4 octal sockets and size of the transformers.
Is that the input jack sitting underneath the OT?
-Jon[/quote]
At present, yes. Again, this is just some spare metal I had around, that I started mounting things in.
First foray into guitar amps. Input jack on the same side as output transformer is bad :?:
ju[/quote]
Yes, putting any of your input circuit near the power supply, or the output transformer and its leads can be problematic.
Marshall and Fender puts the iron on the opposite ends from the preamp. Hiwatt put the OT and PT on opposite sides of the amp, with the OT on the preamp end. But the depth of the box (and very careful layout) allowed them to get away with it.
-Jon
hi guys-
If Im understanding this, could I just build a champ variant and plug a bunch of tubes in there? Is that in essence just what these guys are doing? Champ project was low on my list, but maybe I'll put that on deck.
dave
If Im understanding this, could I just build a champ variant and plug a bunch of tubes in there? Is that in essence just what these guys are doing? Champ project was low on my list, but maybe I'll put that on deck.
dave
some tubes?
i think its a 12ax7 and 6v6
(could be very wrong)
there are schematics on ampage for fender champ stuff.
do you mean just add 14 billion output tubes instead of one?
think that can work but you have to think about the extra current, the change in transformer impedence requirements, etc. you would be better off starting off with a higher power design. what do you have in mind?
i think its a 12ax7 and 6v6
(could be very wrong)
there are schematics on ampage for fender champ stuff.
do you mean just add 14 billion output tubes instead of one?
think that can work but you have to think about the extra current, the change in transformer impedence requirements, etc. you would be better off starting off with a higher power design. what do you have in mind?
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