tweed differences?

[takis]

i did a small search for tweed amps because i always wanted to buy a good tweed amp...i know to what amps to look to(victoria,clark,fender,sdg vintage etc...),but what i wanted to ask is this:

i found infos like this:

3 different deluxes circuits:5c3 (was produced between 1948 and 1952,2 x 6V6GT, 12 watts ),5d3,5e3

2 different vibrolux circuits:5e11,5f11 (1956-1961)

2 different tremolux circuits:5e9a,5g9 (1955-1960)

2 different tweed bandmaster circuits:5e7,super 5f4 (1956-1960)

7 different pro-amps circuits:5c5,super 5c4,5d5,5e5,5e5a,super 5d4,5e4a

7 different tweed bassman circuits:tweed early super and early bassman,second version,5e6,5e6a,5f6,5f6a

6 different tweed twins circuits:5c8(25 watt),5d8(25watt),5e8,5e8a,5f8,5f8a

can anyone tell me which are the differences?why all these...e,f,g letters?:crazy
the sound differences are ...big?i m little confused with all these infos...
thanks!

takis
===========================================
p.s.this is what i found from a member of another forum:

""Basic difference I can see between the different Deluxe models is the tube complement and circuits..

5A3...6N7 preamp, 6SC7 Phase inverter, 5Y3 recto, cathode biased and a "Paraphase" Phase inverter circuit

5B3 &
5C3..6SC7 preamp,6SC7 PI, 5Y3 recto, cathode biased and a "paraphase" PI circuit

5D3..12AY7 preamp,12AX7 PI, 5Y3 recto, cathode biased and "Self-balancing paraphase" PI circuit.
( also apparently no negative feedback loop on this model)

5E3..12AY7 preamp, 12AX7 PI, 5Y3 recto, cathode biased and a "split-load" PI circuit.

All used either 6V6 or 6V6GT power tubes.

Sound difference?? Your guess is as good as mine..however I DO think that the 5E3 has a bit more gain than the others due to the extra gain stage in the preamp,and the different driver circuits might have some influence on the sound of course. The octal preamp tubes have a bit of a different sound from the 12a*7 tubes from what I've heard. I THINK the 5E3 has been generally accepted as a perfect DIY project because of the relative simplicity of the circuit AND the beautiful tone
( subjective opinion of course ).""

[vibroverbus]

i did a small search for tweed amps because i always wanted to buy a good tweed amp...i know to what amps to look to(victoria,clark,fender,sdg vintage etc...),but what i wanted to ask is this:

i found infos like this:

3 different deluxes circuits:5c3 (was produced between 1948 and 1952,2 x 6V6GT, 12 watts ),5d3,5e3

2 different vibrolux circuits:5e11,5f11 (1956-1961)

2 different tremolux circuits:5e9a,5g9 (1955-1960)

2 different tweed bandmaster circuits:5e7,super 5f4 (1956-1960)

7 different pro-amps circuits:5c5,super 5c4,5d5,5e5,5e5a,super 5d4,5e4a

7 different tweed bassman circuits:tweed early super and early bassman,second version,5e6,5e6a,5f6,5f6a

6 different tweed twins circuits:5c8(25 watt),5d8(25watt),5e8,5e8a,5f8,5f8a

can anyone tell me which are the differences?why all these...e,f,g letters?:crazy
the sound differences are ...big?i m little confused with all these infos...
thanks!

takis
===========================================
p.s.this is what i found from a member of another forum:

""Basic difference I can see between the different Deluxe models is the tube complement and circuits..

5A3...6N7 preamp, 6SC7 Phase inverter, 5Y3 recto, cathode biased and a "Paraphase" Phase inverter circuit

5B3 &
5C3..6SC7 preamp,6SC7 PI, 5Y3 recto, cathode biased and a "paraphase" PI circuit

5D3..12AY7 preamp,12AX7 PI, 5Y3 recto, cathode biased and "Self-balancing paraphase" PI circuit.
( also apparently no negative feedback loop on this model)

5E3..12AY7 preamp, 12AX7 PI, 5Y3 recto, cathode biased and a "split-load" PI circuit.

All used either 6V6 or 6V6GT power tubes.

Sound difference?? Your guess is as good as mine..however I DO think that the 5E3 has a bit more gain than the others due to the extra gain stage in the preamp,and the different driver circuits might have some influence on the sound of course. The octal preamp tubes have a bit of a different sound from the 12a*7 tubes from what I've heard. I THINK the 5E3 has been generally accepted as a perfect DIY project because of the relative simplicity of the circuit AND the beautiful tone
( subjective opinion of course ).""

you're basically asking for a books worth of answers... in fact there ARE books that breakdown classic amp evolution like this across versions. my guess is that the answers you get aren't going to help you at this stage (concertina splitter vs. schmitt splitter etc...)

to really be able to understand differences between this many amps you probably need to learn to understand basic amp circuits and interpret what different designs mean. then at that point you can look at any 2 schematics and start to make some conclusions about how they'll be different.

simplest question you asked was about the letters - there's no actual 'meaning' for each letter - they are basically revisions as Leo Fender kept changing and adapting each amp.

[mbratch]

can anyone tell me which are the differences?why all these...e,f,g letters?:crazy
the sound differences are ...big?i m little confused with all these infos...
thanks!The letter went up with each revision of the circuit. Each revision was either what Fender considered an improvement or a cost savings (or both). So a higher letter was a later version. As vibroverbus says, you're asking for book(s) worth of info to cover all those versions of all those amp circuits. You may want to get a book on the history of Fender amps (I forgot the title).

You can look at schematic differences at this Fender schematic (http://www.bnv-gz.de/%7Eooehmann/dexer.php?d=fender) site.

[Wakarusa]

I'll take a crack at the Reader's Digest Condensed version (in no particular order)...

First, the letters and numbers... Tweed models generally start with a '5' (browns with a '6'), then a letter indicating circuit version, then a number indicating model -- '3' for Deluxe, '4' for Super, '5' for Pro, etc. So a 5E3 and a 5C3 are both Tweed Deluxe circuits with the 'E' being a later design than the 'C'.

There are the obvious differences like output tubes (5881 vs 6V6 and how many) and speakers (1x12, 2x10, 1x15). I won't bother going into those.

Next is fixed vs cathode biasing. The fixed designs tend to get a bit more power, but the real difference is more in dynamics and how the amp enters compression. I'd argue that the cathode bias designs are a bit smoother in this respect while the fixed have more apparent headroom.

You've got three basic phase inverter designs. "Long-tailed Pair" in some of the later designs like the Twin and Bassman, "split-load" or "cathodyne" (same thing) in many of the mid to early amps, and "paraphase" in just a few designs. In general the Long Tailed Pair designs will have more apparent headroom because the phase inverter design usually doesn't contribute much to the overall amp distortion. The LTP usually has a more symmetrical output than the other two designs. What this means is that in designs with cathodyne PI's the PI is more likely to break up along with everything else.. and also exhibit some interesting asymmetry (particularly when driven hard) that's part of the "signature tweed" distorted tone. Note that different amps will balance their distortion in different ways (e.g. who breaks up first, preamp, PI, or power section). If you can find one, a 5D4 Super with the paraphase PI is a true thing of beauty when pushed hard.

The older designs used octal preamp tubes (6SC7, 6SL7, etc.). Newer designs used the 9 pin "compactrons" you're used to seeing (12A_7, etc.). The Octals are more difficult to find in current production (a good set of NOS 6SC7 will set you back a fair bit) and can suffer from microphonics. They do sound a bit different than their compactron replacements. Said simply a 6SC7 sounds different than a 12AY7, but the difference is hard to explain. Note too that the move to compactrons also moved to cathode-biased preamps where the octal preamps tended to use grid-leak biasing. I prefer the cathode-biased setup.

In later or higher budget designs the power supply includes a choke in place of a dropping resistor (a PI filter instead of a simpler RC filter). Most of the tweeds have pretty soft power supplies (sag sag sag), but the chokeless wonders are softer still. Think of it as a feature instead of good vs bad.

And, for my money, the biggest difference is in the tone stacks. Three basic designs:
Older/lower budget designs (like the Deluxe) got a simple treble cut. The down side is you don't get a lot of control. The up side is that the tone stack doesn't load down the prior driving stage so many feel it gives a more "open" sound.

Next are what I call the Bandmaster style. There's treble and bass boost/cut in a configuration that behaves pretty similarly to the more traditional Baxendall designs. You get a lot more control at the cost of a bit of circuit loading. I'd argue that it gives just as good a control of tone as the later designs but stays nice and "open" sounding. FWIW, this is my favorite out of the tweeds.

And finally, there's the familiar bridge network that you see in the Twin, Bassman, most Marshalls from past to present and most Fenders from the blackfaces onward. The component values change, but the basic design stays pretty much the same (for an interesting twist, look at the brownface tone stacks with the 350K/70K tapped treble control ;)). With this stack you can have a mids control. The basic tone is the birth of "scooped mids".

Last bit of some interest is that the tweed Deluxe is one of the very few (only?) Fender designs that has no global negative feedback -- further contributing to the very smooth descent into compression/distortion at the cost of reduced headroom.


Certainly not an exhaustive listing, but hopefully helps some.

[brad347]

I'd also point out that it's really hard to learn a lot from descriptions like this (while it is fun). The best way is to play a bunch.

Even with that, I've finally given up on making assumptions about the sound of any vintage amplifier, even from the same make, model, and vintage, because each one truly sounds unique. They have all aged differently and components are mostly 20% tolerance anyway, which means a 100k resistor will be as far away as 120k or 80k, and never more precise than 111k or 89k (due to the 'selecting out' of 10% tolerance resistors).

Furthermore, the old transformers were pretty much hand-wound, and many anomalies exist causing further 'uniqueness' of tone.

Someone saying something has a "5E3 deluxe type tone" is pretty much like saying something "tastes like spaghetti." Sure, that communicates something useful because you know what spaghetti basically tastes like, so it calls to mind certain things. BUT each plate of spaghetti (especially home-cooked!) will taste a little bit different. So it is with old amps.

[Chris Scott]

I'd also point out that it's really hard to learn a lot from descriptions like this (while it is fun). The best way is to play a bunch.

Even with that, I've finally given up on making assumptions about the sound of any vintage amplifier, even from the same make, model, and vintage, because each one truly sounds unique. They have all aged differently and components are mostly 20% tolerance anyway, which means a 100k resistor will be as far away as 120k or 80k, and never more precise than 111k or 89k (due to the 'selecting out' of 10% tolerance resistors).

Furthermore, the old transformers were pretty much hand-wound, and many anomalies exist causing further 'uniqueness' of tone.

Someone saying something has a "5E3 deluxe type tone" is pretty much like saying something "tastes like spaghetti." Sure, that communicates something useful because you know what spaghetti basically tastes like, so it calls to mind certain things. BUT each plate of spaghetti (especially home-cooked!) will taste a little bit different. So it is with old amps.

Too true!

There's the specs on paper, available for any and all to argue basic design parameters and such,


....and then there's the MAGIC!!!!!!!!!!!!!!!!!!

[absenttomorrow]

now if there were only a "spend as many hours as you want playing any type of amp in existence" store somewhere, it would make all of our searches much easier! i feel you takis.

[Wakarusa]

I wasn't suggesting for a moment that all amps of a certain design will be identical; doubly so with vintage gear.

My drivel above was to point out gross design differences under the assumption that takis isn't fortunate enough to have a stable of vintage tweeds and repros to sample, nor the cash to buy one of each. My guess is he's considering buying something blind or trying to narrow his search.

I can see where it would be frustrating if the combined advice I kept getting was: "try as many as you can" and "only some are magical". It tends to give a "search for the holy grail" cast to what may be a very simple desire for a decent amp.

FWIW, I'm pleased to see new builds included in his list with vintage. Sure, some of the vintage amps have aged into something very special, but you're just as likely to get a finicky monster that hums or rattles badly, eats expensive NOS tubes, is dying of board rot, and can't be turned up for fear of blowing a delicate old speaker. A well built clone gets you all or most of the way there on tone without the headaches and risk associated with vintage.

[Boogs]

I'll take a crack at the Reader's Digest Condensed version (in no particular order)...


Thanks a bunch for taking the time to post that nice overview. :cool:

[mad dog]

What Brad347 says is so true. Reading descriptions and investigating specs is OK, but it might surprise you what you respond to. For example. The tweed bassman evolved to a majestic conclusion in the latest, narrow panel version. Yet my favorite of that model is the earlier, two-input bassman with lower wattage. The fixed vs. cathode thing alone is something you have to hear and feel to appreciate. Depends on what you play, how you feel. I still can't decide on that one, had a fixed/cathode switch installed on a tweed type amp and use it all the time ... 2 rather different flavors with the same basic amp.

[vibroverbus]

Even with that, I've finally given up on making assumptions about the sound of any vintage amplifier, even from the same make, model, and vintage, because each one truly sounds unique.

not to mention the most aging-susceptable component in the box: the speaker! take a stack of vintage amps and you'll have every possibility from 'like-new' speakers, reconed speakers, speakers that have been soaked in beer 5000 times, worn out ratty speakers with no surrounds left, speakers whose magnets have been smacked and discharged but are otherwise pristine, etc. etc. etc.

and i like the spaghetti analogy. my blonde piggyback sounds like veggie lasagna with spinach and walnuts. I hope a few cap replacements will give it that meat sauce tone that I've been looking for. might have to dial back the parmesan though.

[brad347]

I wasn't suggesting for a moment that all amps of a certain design will be identical; doubly so with vintage gear.

My drivel above was to point out gross design differences under the assumption that takis isn't fortunate enough to have a stable of vintage tweeds and repros to sample, nor the cash to buy one of each. My guess is he's considering buying something blind or trying to narrow his search.

I can see where it would be frustrating if the combined advice I kept getting was: "try as many as you can" and "only some are magical". It tends to give a "search for the holy grail" cast to what may be a very simple desire for a decent amp.

FWIW, I'm pleased to see new builds included in his list with vintage. Sure, some of the vintage amps have aged into something very special, but you're just as likely to get a finicky monster that hums or rattles badly, eats expensive NOS tubes, is dying of board rot, and can't be turned up for fear of blowing a delicate old speaker. A well built clone gets you all or most of the way there on tone without the headaches and risk associated with vintage.

All of this is so true! And believe me I wasn't trying to "look a gift horse in the mouth" regarding your helpful post. That was all very helpful info for the topic starter and it's nice to see it all in one place. Thanks!

I was just maybe trying to hip him to the realities I've discovered in vintage amps. Like it would be easy to, armed with "too much" knowledge, try one mediocre 5D3 deluxe and then a great 5E3 and then assume "well I don't like the paraphase phase inverter" when in fact it was just a not-too-good example of that particular amp. In fact, it's totally reasonable to bet that somewhere out there there are a 5D3 and a 5E3 that sound more similar than any two 5E3s sound to each other. :BEER

[takis]

vibroverbus,mbratch,brad347,absenttomorrow,mad dog thanks very much for answering!

Wakarusa THANKS for this fantastic post!this is what i wanted to learn..
very general things about the tone of all these amps but importan:BEER

i know that each one may sound different but i took one..all around look of these amps!

for a cheaper solution how close to any of the above amps is fender blues deluxe?

and last question:p :when everyone says about tweed tone,is any of the above amps that is..the holy grail of the tweeds?maybe the deluxe?:confused:

[Wakarusa]

for a cheaper solution how close to any of the above amps is fender blues deluxe?


To my ears a blues deluxe, while a nice amp for the $$, is a lot stiffer/sterile sounding than a good tweed design.


and last question:p :when everyone says about tweed tone,is any of the above amps that is..the holy grail of the tweeds?maybe the deluxe?:confused:


I don't think there really is such a thing as the one true tweed tone. My gross generalization would be that the tweeds sound a bit more brash or raw than later designs, but that the finer points are purely a matter of taste.

Someone else on TGP with a more elegant mind than mine explained it like this (paraphrased):
A blackface is an apple. Shiny, polished, deep and round.
A tweed is a peach. The same basic shape, but with interesting curves and a bit of fuzziness on the outside.

[Clearspider]

A blackface is an apple. Shiny, polished, deep and round.
A tweed is a peach. The same basic shape, but with interesting curves and a bit of fuzziness on the outside.

The perfect analogy for amp types I've ever heard. We need to add some fruits for the others, silverface, browns and then Marshalls, Vox, etc. That would be a great resource for the beginner!

[takis]

thanks again Todd!;-)

[Wakarusa]

All of this is so true! And believe me I wasn't trying to "look a gift horse in the mouth" regarding your helpful post. That was all very helpful info for the topic starter and it's nice to see it all in one place. Thanks!

I was just maybe trying to hip him to the realities I've discovered in vintage amps. Like it would be easy to, armed with "too much" knowledge, try one mediocre 5D3 deluxe and then a great 5E3 and then assume "well I don't like the paraphase phase inverter" when in fact it was just a not-too-good example of that particular amp. In fact, it's totally reasonable to bet that somewhere out there there are a 5D3 and a 5E3 that sound more similar than any two 5E3s sound to each other. :BEER

Didn't think you were doing equestrian dental exams at all. I also agree with your point about not letting a single example of a vintage amp discourage you from the whole line. The differences between iterations of the same design (a la 5D3 vs 5E3) in the same condition (tubes, speaker, level of abuse) should have only subtle differences. There are some huge exceptions like the 5E5 and 5E5-A Pro (huge design changes), but you'd expect those to play differently.

[Wakarusa]

We need to add some fruits for the others, silverface, browns and then Marshalls, Vox, etc.

Heh. No need to discriminate with only fruits...

A Trainwreck is like a marshmallow... fired from a cannon point blank into your face.

[brad347]

Playing my brown 6G4-A super turned all the way up is like walking in a molasses swamp with bubblegum stuck to your shoe.

[Wakarusa]

Playing my brown 6G4-A super turned all the way up is like walking in a molasses swamp with bubblegum stuck to your shoe.

Much as I like tweeds if the shop ever starts to burn, the 6G4-A goes under one arm and the Suhr goes under the other ;)

[brad347]

ME TOO!

I think the 6G4-A is one of the great Fender amps of all time! It's just not always thought of that way...

[vibroverbus]

ME TOO!

I think the 6G4-A is one of the great Fender amps of all time! It's just not always thought of that way...

(as I've said to annoyance probably...) similarly 6G6 Bassmen are also highly underrated. one common design element that Leo was playing with in this era (Brown-Blonde) seems to be higher voltage to pre-amp stages & the PI. typically 300v+ on the PI. I've since had great success with high voltage on pre stages for open clean channels with great dynamic range. of course a 12AX7 datasheet SAYS that 300V is VaMax but who's counting...

[Wakarusa]

(as I've said to annoyance probably...) similarly 6G6 Bassmen are also highly underrated. one common design element that Leo was playing with in this era (Brown-Blonde) seems to be higher voltage to pre-amp stages & the PI. typically 300v+ on the PI. I've since had great success with high voltage on pre stages for open clean channels with great dynamic range. of course a 12AX7 datasheet SAYS that 300V is VaMax but who's counting...

If I'm reading your post correctly, I think you may be a bit confused. The preamp voltages rise some between brown and tweed designs, but go through the roof with the introduction of the blackface line in late '63.

Sticking with our friends the Supers, the 5F4 runs the preamp B+ somewhere around 230VDC for an effective preamp plate voltage of about 150VDC. Same is true for a 5F6-A Bassman. The big difference here is the introduction of the long-tailed pair phase inverter in the 5F6 with a B+ supply of 385VDC leaving (after voltage drop across the plate loads) about 230VDC on the plates. But the plate voltage limit for a tube isn't an absolute value -- it's measured with respect to the cathode. The 5F6 phase inverter runs the cathodes at around 35VDC so, for limit considerations, the effective plate voltage on the PI tube is 200VDC or less. Note too that every tube manual I have sets the max plate voltage for a 12AX7 at 330VDC.

Anyhow, the Browns bump up plate voltage a bit with the PI B+ rising to around 425VDC and the preamp to 250VDC depending on the particular amplifier.

With the blackface line, PI B+ rises to the 440VDC-450VDC range with preamp B+ going above 400VDC. Effective plate voltage (that seen directly by the plates) goes from the 150-160VDC range seen in the tweeds/browns to in excess of 250VDC.

The blackface also replaces the 12AX7 phase inverter with a 12AT7 -- a tube with a max plate voltage of 300VDC, but also increases the size of the LTP tail resistor from 6K8 to 22K. The cathodes are now in the 90-100VDC range with plates at around 300VDC, so the effective plate voltage, even with all of the other changes, stays about the same at 200VDC or so.

The one tube that does get serious abuse in Fender designs is the reverb driver. 400+ VDC on the plates and a 2K2 cathode resistor drives these tubes hard. Some earlier designs had an 820 cathode resistor and would go through driver tubes like Pam Anderson goes through men.

Anyhow, to my ears the magic of the brownface designs is that, tonally, they're about half way between a tweed and a blackface. Still have a nice rawness to them, but can be dialed in for a more refined "blackface" style tone. I've always attributed this to the fact that the brown and black preamp/PI designs are very similar but the browns run at much lower voltages.

[brad347]

to me, a brown is like a blackface where they gave me the midrange back. It's like a blackface that sounds more like a guitar amp.

[vibroverbus]

If I'm reading your post correctly, I think you may be a bit confused. The preamp voltages rise some between brown and tweed designs, but go through the roof with the introduction of the blackface line in late '63.

Todd - not confused, I know Leo progressed on the pre-amps right up to what measures at 270v (modern line voltage) on my BFProR, and of course went to the AT... I still get much higher PI plate voltage on Blonde than BF, although I don't have notes in front of me right now and can't nip out to grab 'em (supposed to be 'working' - what a drag)... I see you're right about the 12ax7 330v on some sources, mine has the 300v - my guess is it's a classic 'conservative' spec?

http://www.mif.pg.gda.pl/homepages/frank/sheets/093/1/12AX7.pdf

[Wakarusa]

Very curious. GE Essential Characteristics 14th ed. shows 330VDC max plate on 12AX7 -- at odds with the GE data sheet you link to. I certainly have no good explanation :)

I'd be interested to see what you're measuring on your blonde Bassman. In the amps I've worked on the voltages all tend to run lower in brown/blonde preamps and PIs than blackface or later designs -- esp. the preamps.