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Blackface vs Brown face vs Tweed

Discussion in 'Glowing Bottle Tube Amp Forum' started by GuitarsBuicks, Jan 16, 2021.

  1. GuitarsBuicks

    GuitarsBuicks Tele-Holic

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    Okay so I have been doing a lot of research lately in my search to possibly replace one of my three amps. I stumbled across a video of the Chris Stapleton signature reissue 62 Brown face Princeton. Before you jump in me, yes I know they are a different circuit, yes I know that amp is ptp as opposed to pcb or some other style of circuit. My question is this. What is the difference between a brownface vibrato, a Tweed amp with tremolo/vibrato(i think one of the had it), and the blackface tremolo(also labeled vibrato)?

    Also what are the major differences between the Tweed, brown, blonde, black, and Silver face eras. I honestly have no clue other than that my SRRI is supposedly a blackface circuit translated to pcb. Anyone with knowledge feel.free to chime in.
     
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  2. strat a various

    strat a various Friend of Leo's

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    That's one of the best questions I've ever seen round these parts. You'll get some good answers when the techies wake up tomorrow. I cant wait.
     
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  3. mojek

    mojek Tele-Meister

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    I can’t wait either:)
     
  4. Fluddman

    Fluddman Tele-Holic

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    I'm not your man for a detailed explanation. But it is clear to me that with each generation, Fender amps became cleaner and cleaner. My first tube amp was Siverface Twin Reverb - 135 watts ultra linear. I new squat about amps back then and couldn't work out why it wouldn't overdrive. Glorious clean sound however.

    Now I mostly play a tweedish 5w champ style amp and tweed deluxe 5e3, they dirty up but still have nice cleans.
     
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  5. jimgchord

    jimgchord Tele-Afflicted

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    Tweeds are run( generally) at lower voltages, they tend to have a spongier, saggier feel and have an emphasis in the midrange, so they tend to sound dirty, even the cleans have an element of dirt when you dig in. As you move towards the blackface line, the voltage ramps up and the power filtering is increased so they tend to feel more immediate and punchy. The eq is more bass and treble with the mids scooped out, the sound is cleaner.
     
  6. Uncle Daddy

    Uncle Daddy Tele-Afflicted

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    Tweed and brownface amps are more mids focussed than Blackface. They tend to have a different way of creating the trem warble too. The earlier versions have a thump you can feel, the BF is less pronounced and more of a flutter.
     
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  7. Dacious

    Dacious Poster Extraordinaire

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    PTP which is components running in mid air, or hand-soldered tagboard (which is what typical vintage Fender up to 84 is) and PCB are all irrelevant to sound. The circuit is the same between a Blackface Deluxe Reverb and a DRRI. Tagboard is favoured for ease of maintenance.amd modding.

    Tweed is oldest, but there's Tweed and Tweed. A Tweed Champ sounds different to a Tweed Bassman which sounds different to a Tweed Deluxe which sounds different to a Tweed Twin.

    Typically Tweed means a simpler circuit. Often with just a treble cut control. Some amps are cathode biased or have no negative feedback, which tends to create a raucous mid-strong, ditty tone. Especially mixed with alnico magnet, undoped low wattage speaker cones.

    Blonde/Brown amps are a development of Tweeds. A 6G2 is the same circuit as a Tweed 5F11 Vibrolux, which is a development of earlier circuits incorporating tremolo which Fender wrongly called vibrato. Browns tend to be a halfway house between Tweed and Blackface eras. They tend to have a smooth but still middy sort of breakup.

    Fixed bias, negative feedback, less raucous. Those amps use an oscillator driven off half a tube to pulse power tube bias up and down to create tremolo.

    Some Brown amps use three preamp to tubes for harmonic tremolo which is pretty spectacular.

    Blackface amps used fixed bias and negative feedback, where inverted signal was fed back in at the phase inverter to smooth harmonics, mostly optical light dependent resistors to turn the signal on and off for tremolo.

    In the BF era there is also a wide variation in tone between different models, but BF/SF era Fender and it's engineers were going for clean, sparklier tones with scooped mids to make reverb and tremolo more apparent.

    Speakers started changing to add power handling, magnets went ferric-ceramic as cobalt which is part of alnico went in hydrogen bombs and Russia had most of the known supplies.
     
    Last edited: Jan 16, 2021
  8. Cali Dude

    Cali Dude Tele-Afflicted

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    I am sure that someone with a lot more knowledge of the inner workings of these amps has already replied, and there will be more to follow. I have gigged with blackface and tweed amps by Fender over the years. As above, the Tweeds seem to be more mid focused, and the blackface amps are more scooped. The Tweeds' breakup is more pleasing to me, but I do like BF OD too. I don't have any experience playing with the brown Fenders.
     
    Last edited: Jan 16, 2021
  9. ruger9

    ruger9 Poster Extraordinaire Ad Free Member

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    This is about the best answer you'll get; without diving into the WHYs (the technical details).

    I'll add that the brown/blond amps were pretty much the same line; so I'd say the Fender line goes: Tweed, Brown/Blonde, Black, Silver. Altho the silver and black are also very similar- a silverface can be "blackfaced" with just a few components changes, I believe.
     
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  10. Wally

    Wally Telefied Ad Free Member

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    Guitarsbuicks, since you mentioned the Stapleton Princeon, Dacious has observed the close relationship that Princeton has with the 5F11 Vibrolux. That relationship continued in the BFBSF Princeton/Prin Rev amps. Yes, the tone stack in the Bf/SF amps changed the circuit considerably. One can add some midrange back in to these BF/SF amps to get to the middier output that exists in the 6G2 and the 5F11.
    As for ‘the tweed sound’, there are some generalities that can be made, but from 1956 through 1960 there are imho at least 5 different groups of amps with five different types of sounds. Before that time, there are perhaps not as many different sounds, but there are dififerences. The small amps...champs, Princeton’s, Deluxes...do not do what the Pro, Super, Bandmaster, Bassman, Twin amps do in those early years. Yes, all of them exhibit more midrange than do the Fenders from 1962 on through the BF/SF era.
     
  11. schmee

    schmee Doctor of Teleocity

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    Good info above. The only thing I will add regarding tremelo is I discovered I really dont like the coveted 3 tube "Brown" tremelo. When I finally had a couple of Brown Supers. The trem sounded like "pitch vary" which I really dont like. I prefer the more BF style. I have had pedals that include the pitch vary or standard trem and I dont like it in them either.
    So it's something to think about in a search for an amp....
     
  12. GuitarsBuicks

    GuitarsBuicks Tele-Holic

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    Okay all of that said, what is the difference between the 64 Super Reverb tremolo circuit and the Princeton/Vibrolux circuit? I know the Blackface Vibrolux is basically half of a Super Reverb by 1964... I know nothing about circuits and the like so I am trying to educate myself.
     
  13. Wally

    Wally Telefied Ad Free Member

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    The Tremolo in the 5F11 is a bias vary tremolo that varies the biasing of the output tubes to create the tremolo. This bias vary tempo is used in the 6G2 Princeton, the 6G3, Deluxe, the BF/SF Princeton/Princ Rev, and the BF/SF VibroChamp and Bronco amps. The larger BF/SF amps have an opto-isolator tremolo circuit.
     
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  14. Viejo

    Viejo Tele-Afflicted Silver Supporter

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    First the Chris Stapelton 6G2 is handwired. The Brownface Princeton and the Tuxedo version the followed are the most Tweed sounding Brownface amps. As Wally said they are basically a 5F11 Vibrolux circuit
     
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  15. Tall-Fir

    Tall-Fir Tele-Meister

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    So what would be the differences in circuitry between a Tweed Champ ( 5F1 right? ) and a silver face champ? I hope this question doesn’t interrupt the fine discussion so far. I am contemplating a purchase.
     
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  16. Wally

    Wally Telefied Ad Free Member

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    the more complex tone stack in the BF/SF Champ is the big difference.

    I originally posted this..
    “The BF/SF has no negative feedback loop.” This is incorrect!!! The BF/SF has more NFB cancellation than does the tweed.
     
    Last edited: Jan 16, 2021
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  17. Wally

    Wally Telefied Ad Free Member

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    just to avoid any confusion, all of the amps that GuitarBuicks mentions are handwired, eyelet board amps...except for the Reissues which he notes is a PCB amp.
     
  18. GuitarsBuicks

    GuitarsBuicks Tele-Holic

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    Okay so next question, is there really that noticeable of a tone/function difference? Is it like MXR phasers where they all basically sound the same way and accomplish the same thing with subtle differences between the Block and Script? I mean my SRRI trem/vib (what ever its supposed to be) doesn't work so I have no clue what its even supposed to sound like. I bought it second-hand from a shop that lied to me and told me when I tested it that the sound difference that I was hearing (the extra Fender Sparkle I had never heard before especially from my Deville III), so I have no clue what the difference is tone wise. I rarely even use the trem/vib function on amps in the store because my number one gig amp has it but doesn't work.
     
  19. Willie Johnson

    Willie Johnson Tele-Holic

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    A tuxedo-knob Princeton 6G2 is the nicest-sounding amp I ever played through. I'm currently using a PRRI and a Silverface Princeton with a boost/reverb as my living room setup and it sounds great.
     
  20. sudogeek

    sudogeek Tele-Meister

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    Wally, I always thought the BF/SF Champ had more NFB than the 5F1. On further consideration, the AA764 has more negative feedback voltage going to V1B (2700 ohm resistor in NFB loop) than the 5F1 (22K resistor). However, the NFB on the AA764 enters between the 1500R cathode resistor and the 47R tail resistor. This would act as a voltage divider. So maybe the effective NFB in the AA764 would actually be less than it appears at first glance, but there is some.

    I built a Champ-like object that could switch between no NFB, 5F1 NFB, and AA764 NFB circuits. It seems, in this CLO, the NFB in the AA764 position is more.
     
    Last edited: Jan 16, 2021
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