The VHT Special 6 is a great guitar tube amp, the circuit is handwired on a eyelet board allowing easy upgrades and modifications…
The main mod that i made on this amp was the Mercury Magnetics transformers upgrade, it costs about three times the price of the amp itself but it makes a big difference in tone.
The power transformer is a Mercury Magnetics FPROJR-P, normally used in a Fender PRO Jr it has more than enough power and fits perfectly in the chassis cutout without any modification.
The output transformer is a Mercury Magnetics SE-9K-M that also fits perfectly in the chassis without any modification.
I also added a Mercury Magnetics CER-OTS100-C 3 Henry Choke, replacing the first power resistor (R24-330 Ohm/5W).
I really like the smooth and creamy tone of the Tung Sol reissue vaccum tubes in vintage style amps, they do also sound great in the VHT Special 6.
In this picture, most of the parts have been upgraded, no modifications on the stock circuit but i did remove the boost option that i don’t use, i did also replace the second input jack by a bright switch with two different voicings (C11).
All of the electrolytic capacitors have been replaced by F&T capacitors (Germany), all of the Polypropylene Capacitors have been replaced by Orange Drop capacitors.
CTS potentiometers, Cliff input/output jacks upgrade and carbon resistors in some places.