I don't remember if Jack Darr's "Guitar Amplifier Handbook" is in PMillett's collection. If not do a google...
There's plenty of info on the net, - spend some search time..
This one is also worth reading - although with a twist..
http://www.tone-lizard.com/
There's plenty of info on the net, - spend some search time..
This one is also worth reading - although with a twist..
http://www.tone-lizard.com/
AuroraB said:
Aye...I'm old enough to have been presented with mysterious black boxes with an impressive fiddled front label spec sheet, the guts only had with a couple of back to back diodes with markings removed...such reputation cost a few Quid (£), claiming fantastic harmonic performers and other mystery injection boxes.Still there is a hi fi amp on the market which looks shiny with an ECC83 lit up on the front panel to 7V and doesn't have one iota of electrical signal flowing through it. And yes it claims class A "tube sound".
Can we all be the wiser and be gaged.....keep ears pricked. Some of us MI'ers have been through this gag.
If you keep to advice through this forum, you'll get something worth running.
richy
This class AB output stage sounds nice with a guitar. No output transformers needed.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1807774&stamp=1240281979
Not recommended for mass production, but fine for DIY (selecting of resistors is needed).
http://www.diyaudio.com/forums/attachment.php?s=&postid=1807774&stamp=1240281979
Not recommended for mass production, but fine for DIY (selecting of resistors is needed).
b_force,
I have all of Kevin O'Connor's books.
"Principals of Power" (POP) is mostly about Power Amplifier Design with some examples of Musical Instrument and Hi Fi Power Amps.
"The Ultimate Tone" (TUT) is the series which is more relevant to guitar amplifiers. It currently runs to 6 Books TUT1 through TUT6.
Of these the following are probably most relevant to you:
TUT3 "Generations of Tone" - Contains complete designs for cloning the "Icons" of Guitar Amplifier tone from Fender Princeton and Bassman, Vox AC30, Marshall Plexi to Ampeg SVT etc.
TUT5 "Tone Capture" also contains complete designs and build instructions for amplifiers including the London Power "Standard" Amplifier which runs that 2 Channel footswitched LPSP preamp I mentioned, has a full tube buffered effects loop, a superior reverb using a 12AT7 push pull driver and a power scaled power amplifier. I built one of these for a friend. It is probably not an easy project for a first time builder and it has a heap more "bells and whistles" than you would ever use. My own amplifier uses a modified version of this preamp, no reverb or effects and a simplified Power Amplifier without the Power Scaling.
I would recommend TUT3 as the book to buy in the first instance.
TUT5 is good if you want to "cut and paste" bits of designs together for your own "flavour" but requires a higher level of knowledge/understanding.
TUT1 and TUT2 cover basic level stuff on power supplies, power amps, and preamps and are good for the beginner. It also covers the most common sorts of modifications done to amplifiers.
TUT4 and TUT6 are the "high brow" books covering Power Scaling and advanced techniques such a GMX (gm multiplication) using a tubes to produce the sound you want and then MOSFETs to scale up that sound. They are for the more advanced guitar amp "tinker".
Cheers,
Ian
I have all of Kevin O'Connor's books.
"Principals of Power" (POP) is mostly about Power Amplifier Design with some examples of Musical Instrument and Hi Fi Power Amps.
"The Ultimate Tone" (TUT) is the series which is more relevant to guitar amplifiers. It currently runs to 6 Books TUT1 through TUT6.
Of these the following are probably most relevant to you:
TUT3 "Generations of Tone" - Contains complete designs for cloning the "Icons" of Guitar Amplifier tone from Fender Princeton and Bassman, Vox AC30, Marshall Plexi to Ampeg SVT etc.
TUT5 "Tone Capture" also contains complete designs and build instructions for amplifiers including the London Power "Standard" Amplifier which runs that 2 Channel footswitched LPSP preamp I mentioned, has a full tube buffered effects loop, a superior reverb using a 12AT7 push pull driver and a power scaled power amplifier. I built one of these for a friend. It is probably not an easy project for a first time builder and it has a heap more "bells and whistles" than you would ever use. My own amplifier uses a modified version of this preamp, no reverb or effects and a simplified Power Amplifier without the Power Scaling.
I would recommend TUT3 as the book to buy in the first instance.
TUT5 is good if you want to "cut and paste" bits of designs together for your own "flavour" but requires a higher level of knowledge/understanding.
TUT1 and TUT2 cover basic level stuff on power supplies, power amps, and preamps and are good for the beginner. It also covers the most common sorts of modifications done to amplifiers.
TUT4 and TUT6 are the "high brow" books covering Power Scaling and advanced techniques such a GMX (gm multiplication) using a tubes to produce the sound you want and then MOSFETs to scale up that sound. They are for the more advanced guitar amp "tinker".
Cheers,
Ian
I have built 5 guitar amps. Some of them SE, others PP.
For clean to crunch tones SE is good. But for rock/metal type tones I do prefer PP. PP does job better - tighter, cleaner, punchier, better bass, you have more of that rrrrrrr in your sound - harder sounding.
Also power supply is very important. Guitar amps uses much much less filtering than hifi amp, wanna know why? Because it sounds better with guitar. I have tried lots of things just to discover how it sounds.
For good guitar amplifier I recommend:
* definately very good OT - with low quality OT, it will always sound bad.
* go for push-pull - suits all playing styles
* use cheap MKT coupling caps - MKP or other suited for hifi doesnt sound good for guitar
* use ceramic caps instead of silver micas
* fixed/cathode bias suites well different styles, fixed for metal definately
There is no magic in guitar amps. Very good sounding amps are just very good tweaked amps by ear.
I just love mine push pull 2x6V6, fixed bias, SLO preamp, OT is Marshall 18W.
For clean to crunch tones SE is good. But for rock/metal type tones I do prefer PP. PP does job better - tighter, cleaner, punchier, better bass, you have more of that rrrrrrr in your sound - harder sounding.
Also power supply is very important. Guitar amps uses much much less filtering than hifi amp, wanna know why? Because it sounds better with guitar. I have tried lots of things just to discover how it sounds.
For good guitar amplifier I recommend:
* definately very good OT - with low quality OT, it will always sound bad.
* go for push-pull - suits all playing styles
* use cheap MKT coupling caps - MKP or other suited for hifi doesnt sound good for guitar
* use ceramic caps instead of silver micas
* fixed/cathode bias suites well different styles, fixed for metal definately
There is no magic in guitar amps. Very good sounding amps are just very good tweaked amps by ear.
I just love mine push pull 2x6V6, fixed bias, SLO preamp, OT is Marshall 18W.
Thank you very much, I will try to find where I can get that here in Europe.
I also have found "Valve Amplifiers" third Edition by Morgan Jones (as PDF form, if you know what I mean
).
Very well written theory, but almost 700 pages, so I think I'll buy that book to.
BTW It is funny, I e-mailed by coincidence with I guy that deals and trades with second hand amplifiers. To make the long e-mail short, he also told of a push-pull configuration (n the Laney Chrome O Zone) that's not driven symmetrical. (the COZ has 4 EL84 in PP, right for 30W). He told me that this is mostly done to get some more bluesy sound of it.
It's about those techniques that you help with the total sound (you like).
I also have found "Valve Amplifiers" third Edition by Morgan Jones (as PDF form, if you know what I mean
).Very well written theory, but almost 700 pages, so I think I'll buy that book to.
BTW It is funny, I e-mailed by coincidence with I guy that deals and trades with second hand amplifiers. To make the long e-mail short, he also told of a push-pull configuration (n the Laney Chrome O Zone) that's not driven symmetrical. (the COZ has 4 EL84 in PP, right for 30W). He told me that this is mostly done to get some more bluesy sound of it.
It's about those techniques that you help with the total sound (you like).
Very good responses in this thread, and they reflect the great diversity in taste when it comes to guitar amps/sound. About 1 1/2 years ago I decided to launch into understanding the subject and started with Kevin O'Connor's books. They are well written, not too obscure, but contain a wealth of information. I would suggest that there is also some value in building one of the clones as a first cut. I'ts habbit forming.
Here's what you are going to find in practice when you try to build a guitar amp:
1. It is NOT a hi-fi amp - meaning it won't act like the hi-fi amps you've built (assuming you have).
2. Everything changes the sound.
3. You can build an exact clone of any amp you want - It will not sound the same almost no matter what you do. (There may be exceptions to the general rule - especially with solid state)
4. If you make one you really like? The next one you build to copy it will not sound the same. (unless you bought double parts or the same exact parts are still available)
5. There is no way to predict the outcome.
6. Guitar amps are predicated upon overload and distortion characteristics - not something that has been studied like reducing distortion in hi-fi amps. So, your guess is as good as anyone elses...
_-_-bear
EDIT: add: High quality OPTs are not "necessary" at all, it depends on the sound you are trying to get, and the specific requirements. Look into "Tone King" amps. Really tiny core transformers, big FAT sound.
1. It is NOT a hi-fi amp - meaning it won't act like the hi-fi amps you've built (assuming you have).
2. Everything changes the sound.
3. You can build an exact clone of any amp you want - It will not sound the same almost no matter what you do. (There may be exceptions to the general rule - especially with solid state)
4. If you make one you really like? The next one you build to copy it will not sound the same. (unless you bought double parts or the same exact parts are still available)
5. There is no way to predict the outcome.
6. Guitar amps are predicated upon overload and distortion characteristics - not something that has been studied like reducing distortion in hi-fi amps. So, your guess is as good as anyone elses...
_-_-bear
EDIT: add: High quality OPTs are not "necessary" at all, it depends on the sound you are trying to get, and the specific requirements. Look into "Tone King" amps. Really tiny core transformers, big FAT sound.
b_force said:Thank you very much, I will try to find where I can get that here in Europe.
I also have found "Valve Amplifiers" third Edition by Morgan Jones (as PDF form, if you know what I mean
Very well written theory, but almost 700 pages, so I think I'll buy that book to..........
I have only a few books on tube amps. My interest has been exclusive to guitar amps so far. Most of what I have learned has been from the internet and from my own builds. I found that Morgan Jones book to be almost irrelevant to guitar amps. I've (tried to) read it probably 5 times and each time I am able to digest a little more. However I still find most of it either over my head or completely unrelated to guitar amps. (I know it's not supposed to be related to guitar amps.) I'm NOT saying it's a "bad" book. It's probably fantastic and 100% relevant to hi-fi aficionados. But to me personally, as a guitar amp enthusiast, it would be the last common tube-amp book I would recommend for learning stuff related to guitar amps.
Yes, this is a great thread! Up until yesterday, my next planned guitar amp was a clone based on the Duo-Class patent. Now, I think I will build it with a "body" control to get more versatility, rather than just having a switch like a Duo-Class. I had not heard of the "body" technique until g'tube mentioned it.
There is something else what I think is a bit strange.
Often you see multiple channel amplifiers (eg the Laney VC50).
What they do is at a switch for bypassing or selecting a second tube to have more gain. The tubes are off course in series.
But if you at another tube, the signal will be Pi rad or 180 degrees out of phase.
Often you see multiple channel amplifiers (eg the Laney VC50).
What they do is at a switch for bypassing or selecting a second tube to have more gain. The tubes are off course in series.
But if you at another tube, the signal will be Pi rad or 180 degrees out of phase.
b_force said:
OK, I had a look at the VC50 schematic, and if I understand you, you are questioning how the switchable section of the Clean channel can be made of 1 triode section, and the Drive channel can be made of 2 triode sections, so that when you switch between channels your signal also switches phase?
Absolute phase is irrelevant in the case of MI amplifiers (except maybe for multiple amping depending on what you are trying to achieve), and it's also mostly irrelevant in most hifi cases (single amp to single fullrange speaker).
M ok, but if your signal is out of phase, don't you get troubles when playing in harmony whit someone else when switching from (call it) low gain to high gain?
For example, when I'm playing with a friend the same piece of music, both signals will cancel each other out (pure theoretical, in practise you have reflections of walls and so on).
To go on with personal taste I've played and listened on quite a few amps and I always liked the sound of the Laney and of VOXes. both an open sound. VOX is really good in clean (especially with the EF86) and the Laney has a really nice open distortion sound.
Orange has it to, but is not as nice at clean sounds and is not versatile enough for me. Marshall is a bit like the Laney in distortion, but I always get the feeling that there is something wrong with those amps (the sound). Call it a bit muddy? (off course all these things are not for all amps!!)
Now I'm trying to find why I like those previous amps that I mentioned. I discovered that the chrome o zone has only a different output stage with the phase inverter completely symmetrical, while the VC50 has a 82k and 100k. There are people saying that those values are chosen because there is always a slightly unbalance. So the difference could be that the VC50 is very tight while the chrome o zone would be more a blues kind of amp?
For example, when I'm playing with a friend the same piece of music, both signals will cancel each other out (pure theoretical, in practise you have reflections of walls and so on).
To go on with personal taste I've played and listened on quite a few amps and I always liked the sound of the Laney and of VOXes. both an open sound. VOX is really good in clean (especially with the EF86) and the Laney has a really nice open distortion sound.
Orange has it to, but is not as nice at clean sounds and is not versatile enough for me. Marshall is a bit like the Laney in distortion, but I always get the feeling that there is something wrong with those amps (the sound). Call it a bit muddy? (off course all these things are not for all amps!!)
Now I'm trying to find why I like those previous amps that I mentioned. I discovered that the chrome o zone has only a different output stage with the phase inverter completely symmetrical, while the VC50 has a 82k and 100k. There are people saying that those values are chosen because there is always a slightly unbalance. So the difference could be that the VC50 is very tight while the chrome o zone would be more a blues kind of amp?
b_force said:
Why don't you try this? If you can even hear a difference, I'll be impressed.
I assure you that respecting absolute phase is not a universal design constraint in guitar amplifiers. Or maybe you've hit on a secret? Maybe the reason why the Beach Boys only used Fender equipment is that they tried just one Marshall 45 one day, but since it inverted absolute phase unlike the Fenders playing, all they heard was silence?
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