In the process of prepping for an audition this week, my board went through its fourth evolution in three months.
There was a time when I really wasn’t big on using pedals. The sound of the guitar hitting the amp, regardless of gain level, sounded better to me.
My first distortion was a BOSS DS1, because I couldn’t afford an MXR Distortion+ and hey, Prince used a DS1 (at least I thought he did at the time). It was horrible. I still don’t like them. It was a “compromise to compensate” (in this case for not owning a Marshall plexi). Around the time tone became “paramount” (1987), someone who contributed a lot to my guitar development got me into the ProCo RAT.
Despite what I thought were shortcomings, I acquired a taste for the way the RAT sounded, adapted my playing and it was part of my rig until it was stolen almost 10 years later (1996 – took the gig bag, left the Twin. HA! weak ass thief).
Until that point, I literally had one pedal between the guitar and the amp. After the robbery, the “one pedal” spot was filled by a TS9 until I started rolling with pedalboard setups a couple years later.
After 2000 I experimented with A LOT of different drives (including modelers). The super linear output section on a Fender Twin leaves a lot of room for preamp slamming experiments.
EVOL 1 began last summer. Determined to become less dependent on gear for tone, I stripped down to a Temple Audio SOLO 18. Even the home brewed joints remained on the bigger board in favor of “stock stuff” from the “tool box”.
Somewhere in the process, a decision was made to keep bigger/original board intact and config the new one to a genre that didn’t need a lot of stuff (I was working on country chops at the time)
Stayed minimal but wanted a bit more “crossover”. I didn’t need the compressor as much for chicken pickin and decided that Tremolo is less cooler than Univibe. There wasn’t enough room for the Rocktron Vertigo (from the bigger board), but plenty for the Moen Jimi Nova (also sounds better than just “decent for the price” +1).
(Note the difference between the Drive settings on the TS9)
After a month or so, the wild hairs started growing in. I A/B’d the modded TS9 against my homebrewed version and remembered the hours spent going through the range of cap values to dial in the bottom (sounds less middy while keeping the bottom tight).
The modded RAT (see EVOL 2 pic) brought a “familiar/safe” lead tone. The wild hairs required something more “outside” for this swap. Rather than pull the Malekko Helium (Fuzz/Octave Fuzz) from the other board, I went through everything I had in the toolbox (including a DS1, modded, still no go).
3 Fuzzes and 1 shitty Distortion led to the most “outside” pedal I owned.
This config was functional until working on material for the audition required a delay with tap tempo AND feedback control (ie. go from 30% to 100%)
EVOL 4a and 4b
Determined to keep the EVOL 3 config intact I added the H9 via the EB Volume pedal doing a split from the boards main out. Dry signal from the board goes through the tuner jack, volume pedal jack goes to H9. I use the volume pedal as an FX send. The expression pedal is mapped to the delay patch’s feedback (can you say a whole day of making infinite ambient pads?).
This worked until I started imagining nightmare scenarios at gigs. I didn’t want to dump the Ekko 616 (analog), but after a week of running the audition set, I was using a single H9 patch for anything needing delay anyway. With the H9 in that spot, this config runs with a single power cord (pedal power has a jack to run the H9), a short patch and two extra cables. The H9 out goes to a separate channel or the other Twin depending on how much room there is.
This is what I’m rolling with (stay tuned)
*all the voices in my head are people I actually know
To fulfill an ambition to become more self reliant with the maintenance of my rig, I began educating myself on the mechanics of my backline. Since 1991 that’s been a post CBS Fender Twin with some minor modifications. If you follow this blog, you’ll know I was able to acquire a second, identical model (with slightly more modification).
A couple of months ago I got an email blast from Gerald Weber (Kendrick Amps) about a couple of Amp Camps. The first being “build your own amp” and the second “work on your own amp”. I’ve been playing with a lot of low voltage, solid state gear for the last 10 years. I figured that using “work on your own amp” camp would be the best way to transition to higher voltage gear, complete with a lowered risk of electrocuting myself.
After a couple of arranged payments, I secured a spot for the camp and started pulling chassis in preparation for the trip.
Day -1: (arrived the night before)
Amp Camp is hosted at the Kendrick Amp facility near Killeen/Ft Hood (TX, natch). My enthusiasm for the event was multiplied by anticipation of getting my first Whataburger since leaving El Paso in the summer of 88.
I was so busy with filling my own orders (Monorocket) that I missed receiving the itinerary email, so I had no idea what the schedule was. I decided that 0800 would be a good guess so I started my day the TX way and headed to Kempner (one town over):
0800 turned out to be two hours early and I was the only attendee at the ranch. Fortunately, one of the Kendrick staff was already there and had everything open. This gave me time to set up, settle in, drink shop coffee and hang out with Geralds dogs (both named Max).
One of the first “other attendees” to show up was someone who attended the previous weeks amp camp. In addition to building the kit, he wanted to work on his gear just like I did. He showed up early to get a jump start on repairs using everything he’d learned so far
Once all the other attendees arrived, things took a more positive turn. Everybody was really cool and friendly. Gatherings like this tend to go either way: either everyone’s really cool and ready to revel in shared interests or each person stakes their own territory and works in isolation. 7 attendees x 2-3 amps each = a good stack of cool gear. There were Bandmasters, Super Reverbs, Bassman heads and even some Ampegs (a Gemini and Flip top bass amp) and a handwired, scratch built JTM45 clone (which was way more immaculate than anything I’ve ever seen Marshall do).
By the time everyone started calling each other by first names, a door opened behind me and in walks Gerald Weber. Without missing a beat after introductions, he launched into a ice breaker joke and started the instruction (I’m not sharing the content – that’s what the tuition pays for)
The only thing I will share is that all of us were guaranteed that everything we were about to do was really easy.
The format was mostly informal and hands on. After dropping some rudiments, we were all sent to our stations to fire up soldering irons and start fixing.
I’ll confess that I did a lot of prep before coming down (helps reduce information overload). I’d even watched a handful of youtube vids that Gerald did. Replacing filter caps and coupling caps before anything else is apparently SOP.
I’ve had my primary amp “overhauled” twice since 1991 and was really disappointed to find out that neither serviceperson replaced any of the filter caps (or most of the coupling caps).
After doing the cap job in both of my amps, the rest of the first day was spent on my primary amp (Norco). The only thing I didn’t do was fire it up for a functional test.
I showed up early again knowing that I could get a head start on amp 2 (Flames).
Better than the hands on training. were the decades of product knowledge between Gerald and Johnny. This was worth the fee alone. These guys have probably seen and forgot more stuff than I’ll ever know. As mentioned earlier the other attendees brought a a wide spectrum of old gear and they had anecdotes and history for each piece.
all recaps complete:
The best part overall was firing up my amps first the first time after doing all the rework.
Prior to coming down the Norco Twin was operating intermittent and the Flames Twin was humming.Both amps were running clean and quiet.
Before I left I’d consulted with Johnny about some mods to the tone stack. I was ready to drill a hole in the back panel for a switch, but he was more than happy to walk me through the mod using the existing BRIGHT switch. Naturally, anyone with this much backstory on the amps knows that the BRIGHT switch is usually on anyway, so why not make that setting permanent and use the switch for something else. I executed that mod before loading the chassis back in their cabinets (after I got home).
Bottom line: I want to do this again. The chalkboard time was primer enough for me to make the jump from PCBs to handwired/IC to tubes. Now I’m prowling the flea markets and yard sales looking for vintage pieces that need repair, to give me an excuse for going through this again.
(reposted from rtopiaradio with edits and amplifications)
(post in progress)
chapter 1 – the origin story
1991 Norco CA – I bought a 1977 Fender Twin (ser A768591) from some guy named Viv, who lived in a geodesic dome.
Date and time unknown – my friend Jim “Flames” Brennan bought a 1977 Fender Twin (ser A769024) from somebody in the wilds of San Bernardino County CA.
Both amps were initially serviced by Smokey “The Amplifier Man” Stover. Both amps had the Pre CBS mods done. They were also completely recapped (including some caps replaced with polystyrene). Flames also opted for Smokey’s “Grunch” mod (which removed the master volume and tremolo and replaced the “intensity/speed” controls with “grind/crunch” controls) .
I’ve forgotten exactly how the “grunch” mod works on a technical level. I just remember that I wanted to keep that part of my Twin stock.
Flames used his Twin (the Flames Twin) until approx 1995 before selling it to a friend.
After nearly 30 years, a couple circuit mods and a few speaker and power tube configurations (KT88’s and currently 6550’s) it’s been my primary amp.
In 2013 I was able to buy the Flames Twin from the person he sold it to. The cabinet was already in bad shape when Flames originally bought it. The repairs that held it together for nearly 20 years didn’t survive the cross country journey (it appears most of the damage happened on on a crater infested section of I40 between Garth Brooks Blvd and OKC – that section of interstate has been improved).
chapter 2 – the reconstruction
The cabs were made from scratch by the same vendor that built my eurorack cases. Theyre solid pine with some joint enhancements (better than CBS did) to make them stronger.
crossposted from rtopia.net (my gear building alter ego)
Got this used on Reverb ($35 – couldn’t pass it up)
Most of the reviews on the Vertigo were pretty favorable. The biggest complaints were “range of speeds via the rate control” and “noise”. Once I got it in my signal chain and worked with it for a couple of hours, I thought it’s attempt at the “univibe sound” was adequate and the ramping (gradual change between settings) RATE/FAST switch was a cool feature (The RATE/SWITCH will either go max rate or whatever the RATE control knob is set to. )
added variable control to FAST option on RATE/FAST switch
extended range of RATE control (wanted a really slow sweep)
replaced LEDS (red/green = zzzzzz)
Items 1 and 2 are documented below (presuming every modder knows how to do TB and part swaps)
This is the PCB and controls out of the enclosure
The switches are hooked in with connection headers (nice touch). I jumpered the ACTIVE switch so the circuit would always be engaged (rate always evident) on either side of the TRUE BYPASS DPDT switch:
While inspecting the board for circuit clues (couldn’t find a schematic) I noticed this diode installed on an LED pad. I was hoping this might be an indicator for the FAST rate. I installed an LED and it didn’t illuminate. I left the LED in (acting as a diode). It didn’t affect the tone/operation of the circuit. It’s interesting that Q7 is facing the LED pad. I wonder if there’s any chance there may have been an attempt at doing a light sensor configuration?
This is the back of the PCB opposite the RATE/FAST switch header (note: pads for LED to the right of the switch pads are tied into LFO section). I removed R57 (10K) and replaced it with a 25K pot (wired as a variable resistor)
To extend the range of the RATE control I replaced R24 (2K) with a 500R resistor.
(note: excess solder flux on the pads in the comb filter section were already there, perhaps these were post run adjustments made at the factory)
RESULTS: worked! (with some conditions)
The FAST control (small knob between foot switches) and the RATE control knob interact with other. Adjusting one will effect the setting of the other. Starting with FAST control knob and setting an initial speed, then going back and forth between the two until I got a FAST vs SLOW balance that I could use didn’t take very long to dial in. Another benefit was being able to dial in more DEPTH for the FAST setting.
With TRUE BYPASS installed, the LEVEL control will always be set to MAX (I also tweaked the feedback resistor on the output buffer to give it a bit more gain)
I attempted to do some tweaks to the comb filter section (changed C22 from 10uf to 1uf) but it started to sound a little phasery (changed it back). I’m gonna run “stock” for a while, analyze a bunch of different univibe schemos and maybe go back in for some tweaks.
In the meantime – I got a day of “Machine Gun” and “Bridge of Sighs” to get to : )