Which Fender Deluxe Circuit?

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Hello

I am considering building an amp using a Fender Deluxe Circuit.
I am unsure weather to use the older circuit (TV front) with the 6SC7 for the preamp and PI.
Or the "newer" circuit employing the 12AY7 and 12AX7.
I am after a warm cleaner sound as I (try to) play jazz.
I want to use my old 10 Watt Goodmans speaker so lower power might be better.
Has anyone gone down this road and care to share?:eek:
 
I can't say I've travelled down that road, but I have a fair bit experience in servicing these things.

First of all, the use of 6SC7 versus the 12AX7/12AY7 does not make all that much difference.
What makes a difference is the PI.

5A,B,C,D3 used paraphase PI's, these can sound really great, but often ask some fine tuning of components. Not exactly plug and play diy.

5E3 was the oddball in the series, as it used the cathodyne/split-load/concertina PI, depending on the guitar/pickups you are using, this might be the best choice.

6G3 and up use long tail PI, so that's basically a mini silver bassman/bandmaster. They also use global feedback, something I wouldn't recommend for jazz. Since the balance (or unbalance if you like) between non-inverted and inverted outputs can be tuned, these circuits are great for blues and classic rock.

And the most important thing is the output transformer.
Since higher frquencies are less important to a jazz player (you would end up turning the treble completely counterclockwise), the best way to go is a relatively cheap oversized transformer. 2-4 times the expected power of the amp.
Someting like the Hammond 1750NA (they say it's a Marshall replacement, but who cares) or an Edcor XPP25-8-7.6K
 
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Now I look at my book closer they do list the 5E3 schematic.
I am using a humbucking Benedetto in the neck position for a pick up on a
carved archtop guitar so it's a bit prone to feedback.
I have to buy a OP TX for this project so that was a timely tip.
Thanks for that.
 
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Ah, the good 'ol 5E3 is a good base to start from to make a good guitar amp. However, some areas should be improved upon considering many new technologies have changed things since then. Now the question is, what do you want?

Considerations:
-Push/Pull or Single ended?
-Reverb and/or tremolo?
-Input stage?
-SS or valve recto?
-Tone controls?

My advice versus what you specified you're after:

Push/Pull 6V6 pair with a cathodyne phase inverter just like the 5E3. That will have a warm guitar tone and allows the use of a tube rectifier (Tube rectos don't affect single ended amps because they draw max current always).

Reverb is always pleasant, but somewhat more difficult to add to amps for someone who hasn't done it before. Tremolo on the other hand is easy to add (takes a single triode, which is half a typical dual triode).

The input stage has 4 inputs for this amp. Do you need four inputs? Each 2 inputs get its own gain stage. If you cut it down to 2 inputs you can recover half the valve (which can be used for other things like tremolo :) )

If Jazz and warmth are your goal then you should keep the tube recto. With the 5Y3 you will get power supply sag but it takes the 5Y3 nearly a half second to swing the voltages.

Now somewhat of a concern is tone controls, the original Deluxe was lacking in this area. In order to get good tone controls you will have to add another tube (a 12AX7/AU7 would be best).


Think upon this and consider what else do you want to add/change. The 5E3 is a good tried and true design but does still have areas for improvement.
 
Yes some good points.
I'm not really worried about reverb or tremolo and only really need a
single input.
I allready built a cabinet around an existing 12" Goodmans 10 Watt speaker
and a old radio/phono chassis with a p-p 35L6 pair of sockets.
Which happily will work for 6L6 tubes also.
So the deluxe circuit seems a good match.
If I can build a great sounding practice amp I will be happy.
If it sounds better than my Princeton doubly so.
 
Old model Deluxes are not commonly felt to be "clean" or "jazz" amps.

The 5E3 is very common to build since it's fairly simple and can sound fantastic.

Yep, I agree.
But this is a new built, so Glowin Plates doesn't have to settle for an undersized and not remotely balanced output transformer like Fender did.
And because of the component and voltage tolerance, some deluxes are biased hot (as they should be) and some deluxes are more centre or cold biased. (talking préamp tubes here)
Same goes for the power tubes, autobias, yes, but seldom biased the way they should be.

All those things can be tuned to create a perfect (and this depends on the player and his ears) tone.
 
OneyedK is right, the more subtle and appropiate alterations can make the tone better. Some people get lost in the "vintage" way of doing things when they really just went with cost-effective methods.

A bigger OT will provide a cleaner responsiveness overall. It can even be oversized to provide even more effect.
 
A bigger OT will provide a cleaner responsiveness overall. It can even be oversized to provide even more effect.

This is true, but most guitar amps are built with undersized power and output transformers. Beefing up these components will produce a result closer to a hi-fi amp. Since most people choose a tube amp for guitar because of their characteristic colour, I would be cautious about stepping too far away from the original specs. You may want a clean tone for jazz, but I would think your best bet is to try and get to play some different flavours of early Fenders and then try to build something close to the one you like best.

w
 
This is true, but most guitar amps are built with undersized power and output transformers.

Trye, but the reason is economical, not tone.
They simply use as cheap as possible components.
(this is actually getting worse with new amps!)

Beefing up these components will produce a result closer to a hi-fi amp.

Sorry, but this is simply untrue. Try it.
(Marshall did it with the bassman, and you know where that ended :p )
Besides, if it were true - and again, it's not, just don't use hifi transformers - the folks at Mercury Magnetics and Weber would have to close up shop real fast.

Since most people choose a tube amp for guitar because of their characteristic colour, I would be cautious about stepping too far away from the original specs. You may want a clean tone for jazz, but I would think your best bet is to try and get to play some different flavours of early Fenders and then try to build something close to the one you like best.

An early Fender consists of components with crazy tolerance, transformers of different makes and sizes and different speakers, most of them no longer available. It's impossible to copy the very tone of one specific Fender. The only thing you can do is buy it. And when it needs service, try to stick to the original values.

But this is a new build, so imho, it's best to choose a circuit that can produce the sound/tone you are after, and fine tune it to preference.
It's a delicate balance between odd and even distortion (and I don't mean with the volume turned to 11) that makes a tone fit for jazz, metal, blues, rock or heavy rock...
 
What he says is true BUT, it's not because you choose an OT with say twice the power needed that the magnetising curve suddenly becomes linear.

Hence what I recommended, and I'll quote myself:
And the most important thing is the output transformer. Since higher frquencies are less important to a jazz player (you would end up turning the treble completely counterclockwise), the best way to go is a relatively cheap oversized transformer. 2-4 times the expected power of the amp.
Someting like the Hammond 1750NA (they say it's a Marshall replacement, but who cares) or an Edcor XPP25-8-7.6K

Once you get to know the effect on tone from an undersized OT, you don't want to go there anymore.
 
What he says is true...

:D

...it's not because you choose an OT with say twice the power needed that the magnetising curve suddenly becomes linear.

Read the article properly. You will see that the desired effect is due to saturation, which has everything to do with not having excess power handling.

Once you get to know the effect on tone from an undersized OT, you don't want to go there anymore.

This sounds like the voice of experience, but my 45+ years of playing guitar and building electronics tell me that you just made it up.

w

I recommend that the OP read those articles before taking anything you say too seriously. It's a beginners mistake to build a tube guitar amp with oversized transformers. Sure, it sounds like a good idea, but many things in electronics, particularly audio, are non-intuitive.
 
Personally I like the sound of saturation. But it is up to the poster with what he wants to go with. He could go with a big OT but I wouldn't. I don't particularly ascribe to too much audio voodoo but I understand what my designs will produce.

I do agree with Peavey along the lines of things that are good for guitar are bad designs. Like for example DC coupled cathode followers.

He could use the bigger transformer if he wanted crystal clean output but then again most transistorized amps produce nice cleans. A good transformer will most of the time not be running close to saturation under normal (and tolerable) listening conditions.
 
This sounds like the voice of experience, but my 45+ years of playing guitar and building electronics tell me that you just made it up.

I recommend that the OP read those articles before taking anything you say too seriously. It's a beginners mistake to build a tube guitar amp with oversized transformers. Sure, it sounds like a good idea, but many things in electronics, particularly audio, are non-intuitive.

Two particularly nasty comments towards me, but I will happily ignore them, because you cannot know how much experience I have and what it's worth.
But choosing the right transformer is no beginners thing ;)

I absolutely agree that the OP should read up on all articles regarding amplifier design.

Let's stay constructive and on topic for now, feel free to pm me.
I recommended
Hammond 1750NA or
Edcor XPP25-8-7.6k
output transformers. Wich I have both used as a Fender replacement.
(I won't use Edcor anymore, because it took very long to arrive and customs fee was pretty heavy)

What do you recommend?

Furthermore, I recommended a loaded 5E3 board from turretboards, because it's more than decent quality and it's a solid base to start from.
(again, I used on of their boards before - bassman-)

What do you recommend?
 
Glowing Plates- I have been down this path and here's what I exp'd with 5E3. I started a few years ago when my Mesa died and rather than shell out near half its value to ship and repair, I decided to learn for hobby, and get and amp I could repair/mod myself. That began the odyssey that-like so many others find-lead into a fun fascinating hobby.

I have a homebuild that I have done many different circuits in using el84s and 6V6-which tube I now use exclusively. The 2 times I have gone the 5E3 have both led away again to ciscuits better suited to modern p/u's. The history of the 5E3 is important point to bear in mind-an economical simple amp that will allow a low bucks entry into electric guitar. In that vein it is classic. But also the guitar it was taylored to is the Tele with low power single coils, then maybe the strat could work too, but most moved on to the fixed bias Fenders as that became the popular sound. Also from what I gather getting the speaker quality correct is very important too for the 5E3 tweed to be successful, and that is likely why I did not get too good of result.

Reading 5E3 threads around-manymany at TDPRI- you find most new builders coming back to ask how to get the bassy flub under control-and esp problematic w/ h/b's. I did what everyone else does-1-5uf bias caps, .011-.022-.047 coupling caps. etc etc. Then works decent with single coils, but not much range of versatility. I have always ended back to some sort of VTB or VTBM tonestack, and cathode biased 6v6's. My current fav iteration is :

Single triode 12ax7 - VTB t.s. - parallel 12ax7/5751 - MV - LTP pi - CutControl - cath bias 6V6's @ 330v on plates and screens. Very rich and harmonic, adjustable to many tones from plexi-ish to compressed bluesy and soft mellow jazz. Tolerates h/b's very well as I use 1-5uf bias caps and lower value couplings. 1x10 and 1x12 speaker combo.

That is my journey as a newb amp maker. Much depends on the guitar&p/u,s and your playing style for sure. We can adapt our technique much to get used to a different type amp, so that is a factor also.
 
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