Machine Gun Amps
Notes on the blackface Deluxe Reverb

This is probably my second favorite amp of all time behind a tie between the blackface Super Reverb and the tweed Bassman. If you have one, DO NOT MOD IT! (other than the harmless tube change I outline below) These little guys are the perfect giggers where you don't need a ton of power or clean headroom. In fact, this may be one of the most famous distorted Fender tones ever, right up there with the tweed Bassman. They really get after it when you crank it, and you'll find that the level it is at when it is cranked is just about right for a rockin 200 person roadhouse or so. Great sound!

1. These amps came stock with a GZ34/5AR4 rectifier tube and 6V6 power tubes. You don't want to use Sovtek 6V6's as power tubes in these, or any other Fender 2 6V6 amp. They simply can't take it. Sovtek built their 6V6 much too weak. 6V6 Fenders almost universally run the plate voltage way over what the specs call for. Old American and European tubes can take the heat, but Sovteks can't. The only new manufacture tube that I'm aware of that can handle this amp and other 2 6V6 Fenders reliably is the Ruby 6V6GTBC. I have these on my tubes page if you are interested, along with NOS JAN Philips, which are about the best 6V6 there ever was.

2. It is possible to install 6L6WGB, 6L6GC, or 5881 power tubes in Deluxe Reverbs. If you plan on doing this, you NEED to get the amp rebiased. I've documented this change on my Deluxe Mod page. Take note that I DO NOT condone mods of amps such as a blackface Deluxe Reverb, but this one is fairly harmless. If you plan on doing this power tube mod, please take heed of the warnings about changing the speaker and filter caps (not applicable to reissue amps). Installing a solid state rectifier will help enhance the 6L6GC sound, but may cause the power supply resistors or other components to fail or make noise. If you plan on using a solid state rectifier, you should expect annoying problems such as noise, but they are easily fixed. DO NOT, I repeat DO NOT use the solid state rectifier with 6V6 power tubes. You have a very good possibility of frying your expensive NOS power tubes if you do.

3. Stock Deluxe Reverb speakers almost universally suck. This is for any year amp actually. Most blackface amps came with Oxfords, which are pretty bad. Not quite as bad as some other Oxfords that came in other amps (Vibrolux Reverb speakers come to mind), but bad. I replaced mine with a few speakers and ended up with a Weber VST C12R. It is a great speaker, and fits the mission of this amp as perfect as you could possibly make a speaker match it. I also tried a JBL D120F, a few no name speakers, and a Weber VST P12R. The P12R is also a great speaker, but less versatile. The one thing it does do, big distortion, is better than the C12R however. But you don't get the nice clean tone that comes with the C12R either. Don't try to use a stock Jensen P12R or C12R because you will blow them in short order. Also DO NOT use the external speaker jack on a stock Deluxe Reverb. The power tubes are stressed enough as it is, they don't need any extra load put on them

4. Silverface Deluxe Reverbs DID get the silverface mods contrary to what a pretty famous tube relabeler and seller said in his books (Hint: the name of the tubes start with G and the ink on them is orange). The only thing that didn't get touched in these was the bias supply. HOWEVER, silverface Deluxe Reverbs have their own thing going and can sound REALLY AWESOME in their own right after removing some of the CBS mod paranoia. The later ones have a really beefey power transformer, and more voltage on the preamp. The result of this is more punch and a bit more headroom. The distortion sound is a bit compromised when compared to blackface, but the clean sound in my opinion is better. If you have a silverface amp, have the amp partially modded to blackface. Actually, the only things NOT to touch are the power supply resistors under the cap pan, and do use a 5U4GB or GZ37 rectifier tube (not GZ34/5AR4). The power supply resistors end up changing voltage on the preamp which is nice. The rectifier tube must stay stock because silverface Deluxe Reverbs in some cases have even higher voltages on the power tubes, which is bad. The power transformer also seems to deliver more B+ current in some circumstances than the blackface one, which is part of the reason the amps stay cleaner as well. A well tuned and serviced silverface Deluxe Reverb can sound like a mini Vibroverb with the right speaker. What a great amp! If you are a blackface Deluxe Reverb owner, try picking up a mid '70's silverface model and have the changes I outlined above done to it. It's a different, and great sound. They are both coming from the same general place tone wise, but different for sure.

5. Have the filter caps replaced and the amp serviced. This applies to any year Deluxe Reverb (excluding reissues). These amps use 16uf-450v power supply caps stock, which should be replaced with the excellent Sprague Atom 16uf-475v's. The extra voltage ability of the Spragues is welcome, and comes in handy when you want to try the 6L6GC/solid state rectifier mod. The bias supply cap is often a 25uf-50v in earlier blackface amps. I usually replace them with a Sprague Atom 50uf-50v. The extra filtering on the power supply is a good idea. But if you like stone stock, the Sprague Atom 25uf-50v is available. The amp uses 7 25uf-25v cathode bypass caps as well (6 in some sliverface models). One other thing for blackface amps: They often used a few reddish brown ceramic disc caps in the preamp and tremolo circuit. These are very often leaky. I find that the .02's are the worst. They usually need to be changed. I use Sprague Orange Drops when I do this.

6. Have fun with one of the coolest little amps in existence!

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Last updated 11/17/00