Vintage Fender Super Reverb Silver-to-Blackface Conversion 1971

Description: To put it simply, “blackfacing” means that you convert the circuit of a silverface Fender amp back to blackface specs. These blackface specs were the designs used by Fender from 1963 – 1967, and are widely considered to be the best sounding amps ever made. This conversion was done by Vintage Sound Amps in 2001 (url: vintagesoundamps). Though VSA make their own brand of hand-wired versions of Fender amps, they also do Fender Silver-to-Blackface conversions, which includes most everything such as a correct vintage Blackface transformer and the correct Blackface tube bias circuit among a list of other things. Based on the transformer code and bias circuit inside the chassis (that I reviewed with the seller's amp tech and his amp book), this one was converted to a 1966. This amp has the original 1970 10" CTS speakers (137 7049N). The power chassis frame is also original from 1971. Also included are the footswitch and a black vinyl Fender-logo amp cover, both are also in excellent condition. I replaced the baffle In 2019 with a new one. I spotted this amp while visiting the fine folks at Blue Angel Music in late-Nov 2011 while I was on a business trip in Pensacola, FL area. For what it's worth, it sounded better than an all-original '66 Blackface that was sitting right next to it. Deciding that I wanted to re-live my (much) younger years (when | owned a '67 Super Reverb), I bought it. Now that l've fully relived that part of my youth, l've decided to let this go from my collection to a new home to live on. If you're looking to buy a VG+++ condition vintage Fender Super Reverb converted to a Blackface this is a real find! Serial numbers: Super Reverb AB763, AB568, AA1069, AA270 A26000 to A29000 - 1967 A27000 to A35000 - 1968 A35000 to A45000 - 1969 A45000 to A49000 - 1970 ****A49000 to A54000 - 1971 A54000 to A59000 - 1972 A59000 to A66000 - 1973 A66000 to A77000 - 1974 A75000 to A78000 - 1975 A78000 to A80000 - 1976 In detail: Modding a silverface amp to blackface specs and what goes into doing so! Silverface amps all sound better when modded back to blackface specs. I will outline the mods below. Suppresser caps: Fender added .002uf (or sometimes 1200pf) capacitors to the grids of the power tubes (pin 5). These bleed off frequencies that they thought were too high to be heard with guitar. The effect of these is to bleed off any frequencies that the amp will oscillate at. Oscillation is like feedback with a microphone. It feeds itself and runs away from you if you don't do something about it. Amps can do this internally, and it's a big problem. The caps are actually a good idea, but they tend to bleed of high end "sparkle" from the amp. These caps were added because of problems with the lead dress that was causing the amps to oscillate. It's unfortunate that Fender needed these. The best way to control oscillation is to design the amp not to oscillate in the first place! But for cost cutting's sake, it was cheaper to put these caps in than spend the extra labor to make the amp more stable. Phase inverter: Fender changed the phase inverter in a few ways. Starting from one end and going to the other: The coupling cap increased from .001 to .01. This has the effect of letting more bass through to the power section. This sounds like a good idea, but to my ear makes the bass get overbearing. The .001 cap sounds tighter with more defined bass to me. After that, Fender used 330k resistors on the grids of the phase inverter instead of 1 meg. The cathode resistor on the phase inverter was made smaller which ran this tube a little hotter. The plate load resistors were decreased from 82 and 100k to 47k. This reduces gain. Overall, the changes to the phase inverter look like they were designed to tame the amp and change the way the amp sounds to what Fender wanted at the time. Reverb circuit: Fender tended to run the reverb driver tube very hot in the silverface years. Blackface amps came with 2.2k resistors bypassed with a 25uf-25v electrolytic cap. Sometime in the 70's, they started to change this value. I've seen 1.5k, 820 and 680 ohm resistors here without a bypass cap. Fender also added a cap from the plates of the reverb driver to the cathode. They added a cap to ground after the reverb tank as well. Bias supply: Fender changed the bias supply from a level to a balance control. The balance control allows the tech to match the tubes, but not set the bias level which is what can determine tone. Also, some extra filtering was added to the circuit.

Price: 3699 USD

Location: Great Neck, New York

End Time: 2024-08-06T13:05:37.000Z

Shipping Cost: 150 USD