B+ voltage off the HT fuse is nominally 432V, in line with typical '68 Plexi 50W voltages.
Below are some additional photos of the completed amp.
Front view with cage and knobs installed. I will redo the Midde and Treble Dymo labels.
Output section wiring.
Power wiring.
Input section wiring.
Switchable mod wiring.
Tone control wiring.
Initial observations playing through IRs loaded by Suhr Reactive Load:
The bright caps increase the noise floor of the amp, especially when the channel has a bright mixer capacitor engaged. Adding gain through the V2A cathode bypass cap does not result in as much noise.
Engaging a bright cap with the bright mix capacitor off on the active channel does not increase the noise floor as much.
I have 2 near-identical channels in shared cathode mode, by engaging the bright mixer cap for the active channel, and turning it off the the unused channel. I can set up four different bright cap values this way.
The 4700pF bright cap (channel 2) immediately distorts the sound as expected.
500pF on a clean sound is too bright, even on shared cathode mode.
The lead channel in split cathode mode is noisy when I turn it up to 10. This is more gain than I need, and I am ok with the noise floor when I dial the amp back to 8 (Fender-scale).
My first pedal project was a Triangle Big Muff using a the 2010 version of a Madbean Mudbunny PCB, built into a gutted Behringer VD1 enclosure. I followed the Madbean Triangle BOM: 2N5088 transistors, 1N914 and 1N4001 diodes, all resistor and capacitors values.
I used pre-bonded 24AWG wire from Smallbear in my earliest projects, which I prefer over the stranded wire from Mammoth and Tayda that I now use. The parts used were mostly from Tayda Electronics, except for the electrolytic capacitors I salvaged a component kit from my sophomore year electronics class.
Guts of the Triangle Big Muff Clone
Old video of my pedal through a Vox Pathfinder amp
Pedal through Fender Pro Junior IV
I started to put together fuzzes/overdrives on veroboard after discovering the Tagboard Effects and SabroTone blogs. I discovered Mammoth Electronics as a source of 125B-sized inexpensive enclosures. Two of the pedals I am currently playing again are the Meathead and Woolly Mammoth fuzzes.
Meathead Clone with switchable input/output coupling capacitors
Guts of Meathead Clone
Video of Input Capacitor Effect in Meathead
The effect of the large values that I chose for the output caps were inaudible. I may switch out for smaller caps in the pF and low nF range, as shown in the alternate layout on the Tagboard Effects post. The effect of changing the input cap is most prominent when using the bridge pickup for me. The 43nF setting is much more audibly different to the 10nF setting than the 20nF setting in terms of bass response.
I tend to keep the Dirt knob low, because my build turned out to be noisy past 12:00. It is also much past unity gain at that point.
I finished vero board builds of a Buzzaround and a Naga Viper based on the layouts from the Tagboard Effects blog (Buzzaround Link and Naga Viper Link). Passive components are mostly sourced from Tayda Electronics. Enclosures are from Mammoth Electronics.
Buzzaround Clone Guts.
The Buzzaround is wired as a -9V effect. I added a 100KA pot for a volume control.
Smallbear PNP Transistors.
I bought a PNP transistor set from Smallbear Electronics. Q1 and Q2 are Motorola-branded transistors of an unknown make, with markings of “9270 336” on the transistors. Q3 is a Texas Instruments 2N404A with a HFE of 140, mislabeled on the bag, but consistent with typical Buzzaround values. I also ordered the 1N270 germanium diode from Smallbear.
Video of Buzzaround Build
Naga Viper clone guts.
I had trouble fitting the vero board into the enclosure due to the height of the electrolytic capacitors I used, so I installed the board at the bottom of the enclosure. Despite the long connections to the pots, the pedal is fairly quiet for much of its gain range. A 2N2222A transistor was used.
Video of Naga Viper Clone through Fender Pro Junior and 5F1 Clone
My next pedal projects are Son of Screamer and Honey Bee pedals using the respective Tagboard Effects vero layouts.
I bought a Green Ringer pedal kit during the General Guitar Gadgets recent sale. I had attempted 2 unsuccessful builds of a Green Ringer on vero board in the past.
The kit came with 2 2N5089 transistors (Q1, Q3) and a MPSA92 PNP transistor (Q2), with 1N4148 diodes.
I had originally tested the pedal by reamping a recorded guitar signal, and came across a persistent hum. I rechecked continuity through all of the solder joints.
However, the effect worked properly when interfaced with an electric guitar’s pickup. The effect seems sensitive to impedance. With a pickup simulator in front of the pedal, the hum was not present.
The pickup simulator is an older build, based on the project on the AMZ website (Link). I used the same 42TL019 10KCT:600CT transformer, with switchable capacitor values based on the AMZ (330pF) and DIYRe (820pF) versions. The transformer secondary is switchable between using the full windings and the center tap to simulate Humbucker and Single Coil pickups respectively.
As I upgraded some of the 2W metal film resistors to 3W on the 1987 turret board, I started populating a board for a future 5E3 head build that I have been putting off.
All passive components are now ordered except for the filter capacitors and a diode for the 1987 board. I am now considering installing a hi/low B+ voltage switch on the Plexi. I plan on using the 625V tap on the ClassicTone 40-18095 power transformer, but am thinking about utilizing the 690V or 560V taps.
The 5E3 will likely be a straightforward build, with little or no modifications. Parts will be Vishay metal film resistors, Vishay MKT1813 and Cornell Dubilier 150 film capacitors, F&T filter caps, Cornell Dubilier silver Mica capacitors, and ClassicTone transformers.
Signal Flow
DOD Carcosa
Way Huge Havalina
Way Huge Saucy Box
BBE Green Screamer
DOD 250
DIY SHO Clone
DIY Fetto Clone
DIY Red Llama Clone
DOD Boneshaker
DIY Distortron Clone
The pedals were mounted with Velcro on a piece of 22”x12” lexan. A Roadrunner All-In-One Pedalboard Gig Bag houses the pedals. A 10-pedal daisy chain is used for power connections. EBS flat patch cables and pancake patch cables were used to interconnect pedals.
All pedals are either DIY or impulse sale/clearance buys.
Video of Green Screamer, Saucy Box, 250, SHO Clone, SD-1 (not on board) boosting a Fender Pro Junior
Video of Jet City JCA22H boosted by the same pedals plus a DOD Boneshaker
