bf-sf deluxe reverb
Post on 08-Nov-2015
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DESCRIPTIONHow to Mod a Deluxe Reverb
BF/SF Deluxe Reverb
Production years: 1964 -1967 blackface circuits AA763, AB763, AB868 (CBS) 1967 -1977 silverface circuits AB763, A1172 and A1270 1977-1979 silverface circuit with Push-pull volume boost.Tube layoutAA763/AB763 Tube layout (Seen from behind, V1 is to the right side) V1 12ax7 = Preamp normal channel V2 12ax7 = Preamp vibrato channel V3 12at7 = Reverb send V4 12ax7 = 1/2 Reverb recovery and 1/2 gain stage for vibrato channel V5 12ax7 = Vibrato V6 12at7 = Phase inverter V7 6V6 = Power tube #1 V8 6V6 = Power tube #2 V9 GZ34 = Rectifier tubeSummaryThe Deluxe Reverb 112 has for decades been one of the most popular amps among all Fender amps, and its popularity is still growing as the demand for low wattage tube amps increases. The combination of size, weight and performance makes the Deluxe Reverb a true road warrior on gigs and practise. Since the year 2002 we have observed, by monitoring the amp market on US ebay, that low wattage amps have increased dramatically in popularity. Nowadays (2012) you can score a big 6L6 vintage Fender amp for the same price as a Deluxe Reverb or Princeton Reverb. We find it irrational. The PA was invented long time before that and guitar tones containing fuzz and distortion have been around since the sixties-seventies. Why has the desire for low wattage amps with 20-25 watts of tube power come up so late?Both the Deluxe Reverb (DR) and Princeton Reverb (PR) survived the CBS silverface periods with minor changes. Many people consider the silverface amps just as sonically good as the blackface models. Being almost a blackface amp with a new faceplate (wrong for collectors), the silverface models became popular value-for-the-money amps. Collectors hunt the blackface models and players hunt the silverface for its quality and price. The push/pull volume boost was installed in 1977 by CBS. The circuit was then significantly different from the blackface circuit. Hence, the price for this amp is lower than its predecessors.The DR is a small/medium-sized amp with an ability to deliver both sparkling clean tones and low wattage breakup at 22W with 6V6 tubes and relatively small transformers (power and output). It has found its way in to more recording studios, clubs and bars than any other Fender amp. It has met many players expectations. It is just powerful enough to cut through in practise in a band with a drummer and, unlike some bigger amps, it will reach its sweet spot at a reasonable volume. It has the typical blackface 60s sparkle with a scooped clean sound just like the bigger Fender brothers, just with more smooth breakup, sag and compression. The smaller brother Princeton Reverb is rolling off more top frequencies and breaks up earlier with more warmth producing a brownface type of tone. It will not cut through the mix as easily as the stingin tone of the Deluxe Reverb.In general we dont recommend the mods on this page that increase the power and clean headroom unless you are playing your amp at gigs on medium/large stages and you need more sparkling clean notes or funky rythm chords to cut through. If you are using your amp at home or in recording situations we think youll be very hapy with a stock DR, and maybe you even want your Deluxe Reverb to break up earlier sometimes. You will be able to shape your tone significantly with just the right speaker(s) and tubes.Youll need schematics to implement some of these mods. http://www.ampwares.com/fender.asp. We usually start with explaining a mod from a functional perspective where we relate to components in the logical schematics diagram. Finally we point out location of components in the physical layout diagram.The Linda Ronstadt amp, a mini-Vibroverb.Let us talk about one of our own gig amps; the Linda Ronstadt amp. It is a 71 silverface Deluxe Reverb that we bought from the Linda Ronstadt band. It came with a fantastic vintage flight case that had travelled around the world, 6L6 tubes, a GZ34 rectifier tube, a JBL D120F speaker and had been totally AB763-blackfaced with new wiring, a professional cap job and all. We were told it had been played by a lot of famous guitar players including the big texan Stevie himself.The amp sounded big, hard and mean with tons of punch and sparkle, a mini-Vibroverb. Unfortunatley it was too shrill and needed to be cranked really hard. Even then there was too much of the ice picky attack in the treble notes. We spent days playing it with different guitars and pedals, not able to decide whether we liked it or not. Maybe this was the reason the amp was sold? It sure sounded nice with a Tubescreamer which removes both the upper treble and lower bass, and this is also how Stevie achieved his tone. But we wanted more. We wanted to play this amp without a Tubescreamer and achieve a decent cranked tone. We finally decided to continue the path that team Linda Ronstadt had started, enhancing this amp to our needs. First we implemented the bright cap mod due to the bright speaker. This easily tamed the upper shrill notes allowing us to use the treble pot beyond 4 (all reissue amp owners with new Jensen C12n, read and learn).We also replaced the GZ34 recitifier tube with 5U4GB and re-adjusted the 6L6-bias to 33-35mA. The 5U4GB removes the instant attack that we struggled with and introduces more sag and compression. Then we pulled the V1 preamp tube and replaced the tremolo intensity pot with a new switchable one that can completly disconnect the tremolo circuit from the signal path when turned to zero (see tremolo disconnect mode below), both to thicken the tone by increasing the preamp gain in the amp. These mods took us 25 minutes including assembling the amp chassis and cabinet back together. The results amazed us once again. The shrill upper harmonic notes were tamed. The pick attack was now acceptable and the hard treble frequencies were compensated with punchy lower mids. It was now much easier to find a sweet spot and good EQ settings and we enjoyed a lot playing the amp with no boost pedals. Even the in-between pickup positions on strats came out quacky and cool without breaking our ears. The amp was now a true texas hot rod amp reaching an approx. 30 watt sweet spot around 3 on the volume knob. The tone reminded us very much of the 64 Vibroverb diaz mod from Fender custom shop, just a little sweeter with earlier breakup. This amp is now definitly a keeper. A few years later we have several spakers in this amp next to the JBL D120F. The Eminence Maverick with an inbuilt 9dB attenuator can turn down the volume to a Princeton Reverb still achieving full tube break up. We are also very happy with a EVM12L speaker in this amp.
What does the Deluxe Reverb sound like?It sounds like most blackface/silverface amps, full American tone with sparkle and punch. Clean tones are great as on all these Fenders. It has 22w clean headroom and breaks up at around 4 on the volume knob with a single coil guitar. The 112 speaker gives a decent spread on stage with rich lower mids and the speaker can alter the tone very much on its own. Five fundamental tricks to create the holy grail of Fender toneSpeakersThe easiest and most effective mod of them all. The speaker is the most important component in your amp which physically produces the air waves that your ears detect as a tone. If you have an original Oxford speaker youll experience a significant change (to the better, in manys opinion) by swapping to almost any other speaker. By most guitarists the Oxfords are considered weak and they fart out in the lows when being pushed hard. Because of the low efficiency youll have to turn up the amp and push the tubes harder to get any volume. The Oxfords have gotten a bad rumor, not rightfully deserved in our opinion. Players who play clean will experience a well balanced and vintage fender correct clean tone. Theyre not too loud and nor do they bother you with a shrill brightness. They do have some vintage vibes and a nice musical voice. Inefficient speakers can be useful in multiple speaker applications 2-4 x10 where the total areal of speakers will provide enough volume for you anyway. Lets see it from another perspective. Youre will not experience any vintage vibe with a brand new Reissue Deluxe Reverb with new tubes and a super efficient Jensen C12n or C12k rated at 50 or 100W; Everything is too efficient with loads of glassy sparkle and attack, some call it harsh and icy. The Oxfords can actually offer the vintage vibe, like it or not.An interesting fact is that the silverface Deluxe Reverbs had better speakers than the blackface amp. The blackface had Oxford while the silverface could have either Oxford, CTS or Utah. Having experienced all these speakers in several Fender amps, we consider the CTS and Utahs to be superior to Oxford, particurlarly in single 112 application requiring high performing speakers that can deliver both punch and sparkle. The good news is that you may get reconed Oxford speakers that sound awesome. There is your ultimate players and collectors amp.Baffle and 210 speaker configurationBy replacing the original 112 baffle with a 210 baffle youll get a bigger sound and more flexible amp. A 12 speaker is slightly harder to drive than a 10 and if youre really into soft touches and finger tips youll probably appreciate the dynamics of 210 more than with a 12. An interesting effect with 12 speakers is the wide 3D spread. While 10 speakers are front directional a 12 have noticably more spread. It contributes to a better sound spread on stage and your band mates will hear the amp better. A nice trick with multiple speaker configuration is to disable speakers in case you need less volume. The output trafo in DR is designed for an 8 ohm load, yet it can be used for 4ohm without any risk for damage. A practical tule of thumb is that all Fender OTs will handle a 100% mismatch in speaker impedance. Example: An amp with a 4ohm OT (Twin, Pro Reverb, Vibrolux) will handle both 2ohm a