BALMORAL ELECTRIC: MKIII / MKIV Tone Benders

Two new MKIII / MKIV Tone Benders finished over the weekend - the circuits have been finished for a while, just had not got around to boxing them up.  Hopefully off to new homes shortly.   Pity Gapco is now out of stock with these enclosures - I should have bought more when I had the chance…

One has a traditional MKIV spec, and the other is more like a D*A*M Fuzzsound / MKIII.  

As a comparison - the main difference between the two is that the D*A*M uses different filter values (tone stack).  A 220n and a 4n7 cap for D*A*M vs 100n and 2n2 in the stock Sola Sound (3.3khz vs 7.2khz).  Basically, the D*A*M has more prominent mids, as the high pass filter on the treble side has a lower cutoff.  Of course, there's a lot of talk about what transistors are used and the impact that has on sound - which I think is more of a textural thing, but I won't go down this road.

The difference with the bias resistors on the base of Q1 also makes a small difference in the frequency response, but nothing significant by the time they reach Q3. D*A*M uses 220k / 47k, which is used in the Sola Sound MKIII Tone Benders, whereas the MKIV uses 680k / 100k.  Check out the tone bender values tables post if you’re interested.