SYT-1100 Upgrade Kit $0.00

This Kit has the following parts:

Choose:

AK12

AK47

AK89

-appropriate saddle to fit the capsule onto the 460* mount

-BV18 transformer that fits into the bell Housing of the 460 donor body.

-Schematic of the 460 microphone and upgrade notes.

-2.2ufd/250v mylar capacitor to replace C8.

-2X62v zener diodes that go into the power supply.

-2X2.2K cathode resistors to replace R7

- EH 6072a pre-tested tube

The stock circuit in a Apex 460, HST-11a, Nady TCM1100 and several other off the shelf Chinese tube microphones can be improved greatly by some simple changes to the circuit which is implemented incorrectly in stock versions.

1) Removing C9 &10 and changing the stock 12AX7 for a selected 6072a tube makes a measurable improvement electronically and sonicaly.

2) Replacing the stock single bobbin with the dual bobbin/bi-metal BV18 transformer further improves the transient response at high SPL's.

3) Lowering the PS supply voltage down to 124v from 144v increases the capsule life and optimizes the capsules performance.

4) The 6072a is now implemented correctly as a CCDA (constant current draw amplifier) which has some amazing benefits in the tube world.

5) This circuit is further optimized by removing C5 & C6.  In a single stage tube circuit the gain would drop 25db without these bypass capacitors.  However, in the CCDA configuration removing these drops the gain 2-3db and the output impedance is now 20 times lower.  The AK12 is a