Other Amps

More tweaky Fender amp stuff- brown/blond/white to black transition

1

Ok the JFK era Fender amps (roughly 1960-63 altho seems like blond Bassmans lasted months in to 1964) were mostly brown, blond, and rough white tolex) with a number cosmetically transitional ones as parts were mixed/matched/used up, etc.

So my theory was/is that since Ampeg had reverb integrated into the amp first, Fender had to get right on it to compete. Ampeg was a real competitor back then --

Is it safe to say integrating reverb into the amp was a fairly major redesign? So I am guessing then that the stuff we like about brown/blond amp scene (complex tremolo - -some call it "harmonic tremolo" for some reason, and presence control) had to go to accomodate trem. Presence was another knob, the the trem used more tubes.

Then it was said in some models (at least my brown Super) there was 1/2 an unused preamp tube that could be wired as an extra gain stage... I remember trying that back in the 90s. Seemed cool enough.

So safe to say brown/blond, etc presence and cool trem was discontinued to get reverb onboard?

2

I'm not familiar enough with the Brown/Blonde amps (seems all my Fender knowledge is concentrated on Tweed and Blackface/Silverface) to know what was removed, but the Blackface era was marked by a standardization of circuits.

The famous AB763 circuit was used in Deluxe, Deluxe Reverb, Twin Reverb, Super Reverb, BandMaster, Showman, Pro, Concert, Vibrolux, Vibroverb, and Tremolux amp models. There were between-model variation in power tube type, rectifier type, inclusion of reverb, number and type of speakers, output transformers, and obviously power rating; but all had the same preamp. There were also some slight differences in tone caps and negative feedback among these amps.

The non-reverb versions (Deluxe, BandMaster, Showman, Pro, Concert, Vibrolux, and Tremolux) were still marked AB763 on the schematic, though they were obviously missing the extra two tube needed for the reverb driver and recovery stages. It's no great secret that the second triode of the reverb recovery tube was used as an active mixing stage for the wet and dry signals, and that therefore the reverb amps have more gain (even when not using the reverb) than their dry counterparts. Still, everything up to, and after, the reverb insertion is nearly identical. There was also the AA165 Pro Reverb, which was very similar to the AB763.

Without going through each of these models' Brown and Blond schematics, I think it's safe to say that the Blackface transition was more than just "adding reverb". The Blackface amp was a completely new design incorporating 3-band EQ, Long-Tailed Pair Phase inverter, Optocoupler Trem, and optional Reverb. The reverb insertion was probably the least complicated of these changes.

Notably the Bassman, Princeton, and Champ (and probably some others) did not receive the AB763 circuit for various reasons, but each did get some of the features during the Black and Silver years.

3

So you sorta skipped over the 4 year period of brown and white... still takes a lot to know it all May be the most overlooked period.

4

It is confusing trying to group the brown/blond amps into one style. Same with the tweed or black/silver face amps. There were many variations with in each group. I have a 1962 Vibrolux which could be considered the smallest of the lower echelon amps. It has 2 5881, tube rectifier and bias vari-tremolo. I also have a 1962 Pro amp which is part of the Professional series of amps with SS rectifier, 5881 tubes and the harmonic tremolo. Both very nice amps but very different. I would have a hard time parting with either one! Both have a thick midrange missing in the later amps but also a clear strong voice missing from my 5E7 amp, which is my only tweed amp. I do have a 64 Tremolux, 67 Bassman and a 74 Deluxe Reverb for comparison. But what do I know!! It's all for fun. Thanks john

5

Well my main question was did the stuff like presence and that rich trem have to go to get reverb in there... maybe we'll never know for sure. This is all coming up on 60 yrs ago.

6

Well the Presence control is just a pot and cap, so I don't think that was a sacrifice made to save space for the reverb. Also the Blackface trend towards more negative feedback probably made the Presence control less desirable to the designer. Was it still actually Leo drawing up the circuits in '63?

The "Harmonic Trem" on the other hand, was certainly expensive requiring 3 tubes and an awful lot of associated parts. And as BZ is wont to remark, it doesn't sound all that good when it's turned off. Personally I find the Opto Trem more useful for music, and if you can add Reverb using the 2 tubes you saved from the Harmonic trem, well then Bob's your mother's brother.

7

So you sorta skipped over the 4 year period of brown and white... still takes a lot to know it all May be the most overlooked period.

– DCBirdMan

Well anyone who messes around in amps should know the Tweed Deluxe and Bassman/Marshall in and out. That's textbook stuff.

As for the Black/Silver circuits, I've actually had my hands inside them. There's a lot more out there, and if you know one, you know em all (to an extent). The Brown/Blonde amps are a lot less common (I don't think I've ever actually seen one in person) and have a lot more variability between models, so there's more to learn.

8

To me it seems that the brown/blond era was Leo's most experimental. Maybe it's that he was searching for a sound and settled when he got to the AB763. Or maybe it's because he sold Fender not long after the AB763 series?

I suspect that when the amps had reverb and tremolo on board the front panel would have had to keep on going if you had a presence control there as well! Although the presence control works on the NFB and is not part of the tonestack it is almost redundant, especially if you have a bright switch too.

I mentioned to a friend who knows a lot more about these things recently about how much I prefer bias tremolo over roach trem and I wondered why the change. His response was the bias trem relies on balanced output tubes and that could get tricky with amps like the Twins with four output tubes - this makes sense to me. But I still like the sound of bias tremolo better. I like the harmonic tremolo too but it uses 3 tubes and a lot of circuit board for an effect you may not actually use that much.

9

I always thought the bigger amps didn't use bias trem because the LFO circuit didn't have the amplitude to vary the bias voltage to the 6L6s enough. The photocoupler works regardless of the relative voltages of the LFO and the bias.

That, or Leo really wanted the two channel amps to have a fully dry channel.

I reckon matching tubes was pretty commonplace in an era when you could buy your 6L6s--and test them--at the Five and Dime.

10

I can never find much evidence of the Blonde era being very popular TBH. Townshend and Harrison a little, Setzer made it his own of course.Is there any simulation of a blonde bassman anywhere? No one bothers with that. And before someone says Tech 21 Blonde... Its just a setting somewhere somehow in the centre voice setting. Soz

11

I can never find much evidence of the Blonde era being very popular TBH.

The Beach Boys toured with them for much of the 1960's. When I saw the Rolling Stones after they returned to the U.K. from their first U.S. tour in 1965 they had them too.......I'd never heard anything like that before. My Vox AC30 that I had at the time was wimpy by comparison.....and it's a loud amp!

12

I can never find much evidence of the Blonde era being very popular TBH.

The Beach Boys toured with them for much of the 1960's. When I saw the Rolling Stones after they returned to the U.K. from their first U.S. tour in 1965 they had them too.......I'd never heard anything like that before. My Vox AC30 that I had at the time was wimpy by comparison.....and it's a loud amp!

13

I do like the brown Deluxe, but really a well-sorted tweed is my favourite of the Deluxes. The tweed Vibrolux with a 12" speaker is a beautiful thing too. There is something about the simplicity of those tweed circuits that I really like - with a few tweaks you can update them to get many beautiful, complex sounds that more complicated amps can't get.

It seems to me that as amps become more sophisticated they lose the subtleties and character of the simpler circuits.

14

I can never find much evidence of the Blonde era being very popular TBH.

The Beach Boys toured with them for much of the 1960's. When I saw the Rolling Stones after they returned to the U.K. from their first U.S. tour in 1965 they had them too.......I'd never heard anything like that before. My Vox AC30 that I had at the time was wimpy by comparison.....and it's a loud amp!

– Yavapai

Au contraire, mon vieux….. During the Brownface era, the blondes were the high-end professional amps, and all us garage-band guys left many a noseprint on music-store windows, which was as close as we were gonna get to the good stuff on garage-band money. The Tremolux was the cheapest at $279.50 list-- in today's anemic bux ,that's $2430USD. And EVERYBODY paid list.

Another reason you don't see blondes very much now is that the instant the blackfaces came out, most folks who did have blondes made with the black spray paint.


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