BTW, the Costa Mesa show was pretty sucky & not well attended. The best deal there was a Takamine top of the line 12 string for $600 if that tells you anything. Very few offsets and very few amps.

Keep it Drippy Brothers and Sisters!

My best guess is 8-9 hours actually building the Encore. There was extra time taking inventory of all the pieces and I spent a bit more as the power tubes that came with the kit where poorly matched (one was junk) and needed to be re-sent by Mr. Allen, not his fault. I spend a bit of extra time with lead dress. It makes for a quiet amp and it looks cool. My quote was $300 for the labor to build the amp. My final payment came with a $200 tip.

There are pics posted in my profile at www.fenderforum.com. I'm Hammond101 there too. If you go looking at pics check out the "Radio Amp". It's a 1935 Stomberg-Carlson floor model radio that I stuck a tweed Princeton circuit in. I used the old chassis and made no cosmetic changes to the exterior of the cabinet.

Check out the low power tweed Twin build as well. My favorite amp for a blues/classic rock gig. Also posted is a BF Vibroverb I built from a restored original AB763 Fender main board I found on ebay.

One of these days I'll figure out how to post pics here.

Keep it Drippy Brothers and Sisters!

Last edited: Sep 09, 2014 23:59:49

Hammond101 wrote:

There are pics posted in my profile at www.fenderforum.com. I'm Hammond101 there too. If you go looking at pics check out the "Radio Amp". It's a 1935 Stomberg-Carlson floor model radio that I stuck a tweed Princeton circuit in. I used the old chassis and made no cosmetic changes to the exterior of the cabinet.

What a nice library (like the McLaren pic too). Some very cool builds & your attention to detail is evident; the VV came out beautimous.

I go back to your mention of a 'star' ground concept utilized in the Allen. I thought I'd seen other amps doing a daisy-chain or just willy-nilly tied to whatever's convenient. I don't do that with my HF radio gear, and such a notion with some Army commo rigs (tied to a generator out in the bush back in the day) would get your Ashtabula knocked to the ground. I would think this tends, as in radio, to eventually introduce an overall noise-level in the system that doesn't have to be there. Why do they do that?

Thanks again for sharing the pics.

Wes
SoCal ex-pat with a snow shovel

DISCLAIMER: The above is opinion/suggestion only & should not be used for mission planning/navigation, tweaking of instruments, beverage selection, or wardrobe choices.

The only Allen I've really got my hands on is this Encore. They are rather rare, most home built and serviced. I found it very BF with a lot of clean headroom available. It all depends on how you set up the controls. It will just sparkle. My testing was with an EV SRO-12L in a closed back ported guitar cab as the owner of the amp did not ship the cabinet to me, only the chassis pieces for assembly. The post PI master volume in the Encore is excellent and very useable. It is a very versatile amp. Oh baby that raw control! It can make a real snarling beast out of it.

Can't beat a star ground for the preamp/control section connected to the chassis as close as possible to the input jack. Very quite.

Grounding in radio gear with a transmitter I would think is critical. Screw that up, key the mic and as David Hobbs say "Kablamo".

Thanks for noticing the McLaren photo. I have a shot of just the intake velocity stacks on an orange M8A matted and framed hanging above my fireplace. I get a lot of "WTF is that" from my company. CanAm in the late 60s and through the mid 70s was the best racing I have ever seen.

Keep it Drippy Brothers and Sisters!

Hammond101 wrote:

Thanks for noticing the McLaren photo. I have a shot of just the intake velocity stacks on an orange M8A matted and framed hanging above my fireplace. I get a lot of "WTF is that" from my company. CanAm in the late 60s and through the mid 70s was the best racing I have ever seen.

Great, you just dated yourself , and I agree about CanAm. Stacks = Sculpture. Have a dear friend, whose affliction to NASCAR I forgive him with simple: "Oh, yeah, the ones that just turn left...."

Yeah, ground loops in HF sometimes to fill the room with RF instead of the atmosphere to do the work & make the antenna into useless wire. Oddly, older tube rigs are much less susceptible to anomalies in standing wave; but current-gen SS not likey much at all, most unforgiving.

Wes
SoCal ex-pat with a snow shovel

DISCLAIMER: The above is opinion/suggestion only & should not be used for mission planning/navigation, tweaking of instruments, beverage selection, or wardrobe choices.

Last edited: Sep 10, 2014 12:58:37

Hammond101 wrote:

BTW, I've done some endurance racing in Karts at Road America in your state now. Circa 2001 I managed, engineered and drove for a team 100% sponsored by American Honda. I built, tuned, setup and drove. I was still fast in my late 40s but the older I get the fast I was

Hey, easy. I resemble that. Nice track that one, but you already got my head back into seeing Donahue come down the Corkscrew... Did some F-Ford during time in Europe (mid-70's); damn we were poor. Oh well, back to things I can afford.

Wes
SoCal ex-pat with a snow shovel

DISCLAIMER: The above is opinion/suggestion only & should not be used for mission planning/navigation, tweaking of instruments, beverage selection, or wardrobe choices.

Nokie wrote:

WetBandit wrote:

Nobody seems to like the custom vibrolux reverb. I played one recently and didn't notice any hissing or humming, thought it sounded great, nice dirty tone if that's what you're shooting for. I thought its still had that nice fender sparkle along with the dirt. I know it's not a actual reissue of the vintage vibrolux. But is a very nice, loud good surf amp And garage tone amp.
Does anybody like this amp stock besides me?

I love the Custom Vibrolux but like any amp, it depends on your playing technique. The Custom Vibrolux is not for outdoors if you've got a loud drummer. Mine has a bit of hiss due to the lack of a negative feedback loop. That's a feature that makes it a very responsive to picking attack. It does have a sweet spot near 5. The reverb is quite weak but I prefer the outboard tanks when reverb is needed.

Agreed, until I did the Moyer mod, swapped tubes and replaced the speakers. Now this is a killer surf amp, no doubt. Put some NOS tubes in it and the speakers were replaced by Ragin Cajuns. Here's a demo (not my amp, so I don't know about the speakers) which gives you an idea of how fantastic this amp can sound with some modifications. The trem is also excellent and the hiss/crackle is gone: Click
Oh, and it can stand against a loud drummer now. The speakers were the issue.

The Hicadoolas

Last edited: Sep 12, 2014 00:34:32

Where does a guy like me get the Moyer mod done?

"Hello Girls!"

Last edited: Sep 13, 2014 12:18:03

Just about any competent tech who does tube amp work should be able to do the Moyer Mods. All they would need is Mark Moyer's mod sheet I have copied in below. I have done a few over the years however elected to sell my personal CVRs rather than to mod them.

Here you go:

"CVR Moyer Mods

Modifying Converting a “Custom” Vibrolux Reverb into a ’63 Vibroverb By Mark Moyer

The Differences:

1. Reverb is present in the ‘Verb only on the bright channel. It is on both channels in the ‘Lux. This is accomplished by connecting pin 6 of V1b to pin 6 of V2B and eliminating R35, and R11, V1B’s plate load resistor (220k in the ‘Verb), and using the R22/R23 combination as a common plate load resistor for both V1B and V2B. On the ‘verb, R22 and R23 are 22k and 82k, respectively. On the ‘Lux, R23 is dropped to 47k. The Lux has a significant amount of hiss and more pre-amp gain with lower headroom due to this circuit change.

2. The Lux has a 500pf-coupling cap from the 12AX7 of the Reverb return to the pot. The Verb uses a .0033uf.

3. The ‘Lux has no negative feedback. The ‘Verb has a NFB loop. Negative feedback loops tend to negate hiss and other unwanted noise.

4. R37, the lower cathode resistor in the PI, is 6.8k in the ‘verb and 39k in the ‘Lux.

5. The ‘verb has a 100pF shunting cap, C20, across the PI plates. This is absent on the ‘Lux.

6. The ‘Lux has 3kV spike protection diodes on the OT.

7. The ‘Verb has very cheap sounding Oxford 10K5 reissue speakers. The ‘Lux has the decent-sounding Eminence alnico’s.

8. The Original Vibroverb runs a 12AX7 with a 1k 1w-cathode resistor as its Reverb driver. The Lux and Verb run a 12AT7 with 2.2k 1w.

9. The Verb’s ground reference resistors; R62 and R63 are 47ohms. The Lux uses 100ohm

The Changes

1. Reverb on both channels. This is a neat idea but IMO the negatives outweigh the positives. Adding Reverb to both channels of the Lux causes a significant amount of hiss. Going to a common plate load resistor and lowering R23 from 82k to 47k makes the pre-amp run hotter, which to my ear makes for less headroom. I also suspect some cross talk is going on.

Further, the Reverb on the Bright channel improves by converting the Lux pre-amp back to the Verb. If you like Big Clean Reverb laden tone with no hiss you must convert the Lux pre-amp back to the Verb. To convert the Lux pre-amp back to the Verb unsolder the blue wire from pin 6 of V2 and solder it to the unused hole marked 6 on the circuit board where the rest of V1’s connections are made. The blue wire connects pin 6 of V1 to pin 6 of V2. Leave one end connected to pin 6 of V1. Replace R23 with an 82k. Place a 220k resistor in both of the empty spots pre-marked R35 and R11.

1. Fuller Reverb: The Reverb on the Lux is much more filtered out then the Verb due to the coupling cap in the recovery stage. C16 on the Verb is a .0033. On the Lux it is 500pf. This is a significant difference. I highly recommend replacing C16 on the Lux with a .0033 Silver Mica cap. This makes the Reverb come alive on the otherwise Reverb challenged Lux.

2. NFB: To further reduce the hiss found on the Lux and increase your headroom you must add a NFB loop to the ‘Lux. Solder a 10k resistor in the empty space marked R41. Then run a wire from the speaker jack (positive, or tip, terminal) to the unused connection point ‘2’ above the right-hand corner of C37 and next to a green wire. ONE MORE THING! There needs to be a 470-ohm resistor between this point and ground! It’s R42 on the Vibroverb PCB. My 1995 Blonde had a jumper wire acting as R42. One Other Phase Inverter Change: Replace R37 with a 6.8k resister. This goes hand in hand with the NFB loop change.

3. Shunting cap: The Verb has a 100pf-shunting cap across the plates of the 12AX7 Phase Inverter. It is C20. I recommend placing this 100pf cap in the Lux as it is inaudible and greatly reduces the parasitics that are inherent with a printed circuit board.

4. Surge protection diodes: While theoretically these diodes are a good
   idea. In practice I have found them to be more trouble then they are worth. They tend to cause the amp to blow fuses when switching from stand-by to on. Further, they seem to drain off some of the high frequencies. I am talking about the diodes from pin 3 to ground on the 6L6GCs. None of the older Fenders had them and most of these amps are still going strong 30 or more years later. I recommend removing these Diodes.

5. Ground Reference Resistors: Replace R62 and R63 with a pair of 47ohm resistors. I used 1-watt metal oxide. This may seem an insignificant change but it removes the last little bit of hum and hiss form the amp.

The Options:
1. Installing a Bias Pot: Use a 10k linear pot. Mount the pot through the bottom of the chassis below and to the pilot-light side of the tremolo pots. Remove R59. Solder two lengths of wire to the PCB where the resistor was. Connect one of the wires to the middle and one end tab of the pot. Solder a resistor to the remaining tab and connect the other end of it to the other wire. For values, I recommend starting with a 10k. What you’ve just done is replaced the 18k bias set resistor with a 10k resistor in series with a 10k pot. Where before you had a fixed 18k, you now have 10k-20k range. Button things back up and check your idle current. You will want to see anywhere from 30-40mA per tube. If you can’t get the idle current high enough (which is likely if you use NOS American tubes or the Telsa 6L6GC), replace the 10k resistor you just added with a 5k. If you use Svetlana tubes the 10k works fine. Phillips 6L6WGBs may require the 5k. The Telsa 6L6GCs will definitely require the 5k. I have tried the Svets, Phillips and Telsas in my amp. The Svets have nice mid range. A good sounding all around tube. The Phillips are clean and bold at low volume and break up nice. A good blues tube. The Telsas remind me of 7581As. They are big, full and clean. They seem to add wattage to this amp with lots of big clean headroom. They are also tough as nails and can be run hard. The Svetlana are my choice for this amp. I run them @ 36ma per tube.

1. The Original Vibroverb, not the re-issue, ran a 12AX7 as its Reverb driver. Replace R26 with a 1k -1w resistor and install a 12AX7. The 12AX7 will increase the dwell of the Reverb and is a much more common tube if you want to experiment. Be sure to use a 1-watt resistor here! You may find that this gives you too much Reverb.

2. Reverb Switching: These amps always have some Reverb, even when it’s turned down to ‘1’ and foot switched out. All Fender Reverb amps do this to some degree, but on these it can really be annoying, especially when cranked.

The solution is to rearrange the foot switch setup to the original Fender style. On the ‘verb/Lux, the foot switch grounds the signal from the Reverb recovery circuit at R65. This should kill the signal, but for some reason it does not. On the original Reverb amps, the foot switch grounded the Reverb signal at the grid of the recovery tube. It’s simple to put this back in order.

First, trace the gray wire attached to the foot switch jack back to the PCB. Either unsolder it at the PCB or just snip it off flush. Then solder it to pin two of V4. Viola!

1. The stock Reverb cables are crap. Replace them with some nice heavy-duty video quality cables. I disconnected the originals from the board and soldered the new cables right to the board. This improves the signal quality and reduces interference making for better quieter Reverb.

2. As in all Fender Reverb amps the 12AT7 Reverb driver takes a beating. A good fresh RCA or Mullard will last the longest and sound the best. I tried the Phillips 12AT7 and I was disappointed with its short life and shallow tone.

3. As you may have noticed, I am a Reverb junkie. I like the smoothness of the three spring Reverb pan in this amp. The number is 9AB3C1B.

4. There is a 47pf cap across the volume pot of the Bright channel. This is what makes the Bright channel Bright. This is the same set up as the Deluxe Reverb. I feel that the amp is too bright with this cap. If you share my opinion simply remove C11. It is on the Bright channel daughter board. For what it is worth, I remove the 47pf cap from the Deluxe Reverb as well.

5. The stock blue Alnico speakers are decent but there are better. After much research I decided to buy and install a pair of the Weber C10Qs. This final change was the icing on the cake! They transformed my already fine sounding amp into a truly professional sounding workhorse.

The Conclusions:
The Fender Vibroverb, in my opinion, is the best sounding amp that has come out of the Fender factory in years. I am very big on REVERB and the Vibroverb, when properly set up, has the finest Reverb of all!
Converting a Lux into a Verb is fairly simple and will take you about an hour if you know what you are doing.
My goal in converting my 1995 Blonde Lux into a ’63 Vibroverb was to get rid of the hiss. I also had a parasitic on certain notes. Further, the Vibrato would make an audible pop when I switched it on and off. I liked the basic tone of the Lux but I could not live with the noises and shallow Reverb. Converting my amp made it virtually silent. The basic tone is about the same but the Reverb is much bigger and fuller. I do not miss the Reverb on both channels. I do not miss the pops, crackles and mostly I do not miss the Hisssssssssssssssssssss. Mark"

Keep it Drippy Brothers and Sisters!

Hammond101 wrote:

I liked the basic tone of the Lux but I could not live with the noises and shallow Reverb. Converting my amp made it virtually silent. The basic tone is about the same but the Reverb is much bigger and fuller. I do not miss the Reverb on both channels. I do not miss the pops, crackles and mostly I do not miss the Hisssssssssssssssssssss. Mark"

+1...no actually +1000! The Vibrolux is such a great amp after the mod. You won't believe it until you hear it. Any good tech should be able to do this at a reasonable price. If you need more info, feel free to pm me.

The Hicadoolas