Two modified Traynor YBA-1 heads

V2

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USD$800 + shipping for either amp.
Add $100 for old-stock Philips tubes in place of new-stock tubes (only one set available; otherwise amp will have full complement of new tubes)
Add $50 for original vinyl cover (only one available)
Subtract $50 if you want the amp without tubes (use your own).

Completely overhauled YBA-1 amps from the mid 70s. Serviced and modified.

** Service and updating for each amp **
- New 12000-hr caps loaded on my own custom PCBs
- New grounding scheme and some power supply tweaks to make the amp WAY quieter, even with way more gain.
- New 3-prong power cord (with ground switch and death cap removed) for safety.
- Bias trim pot added for quick bias adjustment.
- Original fragile wires replaced for reliability (essentially, all original wires will break if lightly stressed).

** tone mods, Amp 1 **
Similar to single-channel Friedman Smallbox, with Low- and High-sensitivity inputs for 2 or 3 gain stages, respectively. Depth knob on rear panel. Mini switches for bright/bite (three position), gain structure, Fat, and 'era' (low/high gain for high-sensitivity input).

** tone mods, Amp 2 **
Single-channel SLO-based mod with low- and high-sensitivity inputs for 3 or 4 gain stages, respectively. A solid-state source follower was built on a custom PCB to drive tone stack (since I didn't want to drill the chassis for another 12AX7). SLO preamp values tweaked a bit, similar to what Baron55 recommended on the SloClone forum. Depth knob and Fat/tight switch added on rear panel.

Amp #1:








Amp #2:













Cover:

 
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Sct13

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These are great amps!

I have a 1967 YGA-1 signature .... plexi madness
 

redking

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This is a killer 2 amp rig for someone!
 

V2

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A terrific 2-amp rig, but each amp is available separately too :)

Each amp has adjustable fixed bias now. Roll those power tubes!
 

V2

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Update. Surprisingly, I still have these amps. I haven't been in a hurry to unload 'em, in part because I wanted to continue to mod the amps.

Amp #1 - USD$900 plus shipping
One amp (formerly based on my dual-input Vibe) is now a kick-ass Caldera. Single channel, BE/Jose-type circuit (without clipping). Low-sensitivity input gives a "plexi" mode with two gain stages. High-sensitivity input gives higher-gain mode with three gain stages. Front panel sports three-position Bite switch and punch (gain structure) switch. Rear panel sports FAT switch and Era switch to fine tune how much gain is possible in the high-sensitivity mode. So even without the gain-structure switch, there are three different gain 'modes': low (plexi), medium (plexi+), and high.

Newly tubed, recapped, and totally reworked.


WhatsApp Image 2020-08-25 at 6.37.15 PM.jpeg




Amp #2 - USD$900 plus shipping
The other amp is now based on the Soldano SLO. Single channel, rear-panel FAT switch to tighten up the low end. Only one pair of inputs is wired up; others can be removed, depending if you want to maintain the vintage look or not. Tech details: the YBA1 doesn't have enough preamp tubes for the SLO. In such situations, many builders drive the tone stack from the plate of the fourth gain stage and simply omit the cathode follower (think Splawn). I did something different: I designed a solid-state 'source follower' PCB and dropped it onto the eyelet board. It works very well! Low- and high-sensitivity inputs to give you some flexibility with gain (3 or 4 gain stages, respectively).

Newly tubed, recapped, and totally reworked.

01717_bA2KDyPFyz3_0CI0t2_1200x900.jpg


IMG_20200828_121732.jpg
 
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V2

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First post updated with new photos and prices. Here are some clips:

Amp 1 ('friedman' type preamp):

Amp 2 (SLO type mod):
 

V2

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Amp #1 is sold.
Amp #2 is available, but since I have the urge to mod, I'm going to turn the preamp into a Roccaforte HG100. :)
 

V2

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The Rocca circuit sounds great. Improved wth a low-sensitivity input (3 gain stages), depth know, audio gain and master pots, bright switch, tight switch, and soon PPIMV. Local sale pending...
 


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