Page 67 - Triwatt Custom Lead Amp Builder's Guide

Appendix 4 - FAQ

Q: Where can I find more help and support?
A: Sign up at the Trinity Amps Forum and check the “Resources” section or post a question in
the TRIWATT, Lightning Strikes or, 18 Watt forums.

NOTE: B+ stands Battery Plus == B+ and came from the old days of tubes. B+ is measured at
the intersection of the rectifier DC output and the first filter cap.
On a TRIWATT, it is measured between the joined lugs of the 50+50 cap and chassis ground. It
should be about 450 VDC with tubes, with 120 VAC mains.

Q: Does it make a difference as to what orientation I choose to make sure the power switch
operates correctly, i.e. on is on and off is off?
A: It does it make a difference as to what orientation you choose to make sure the switches
operate correctly. Put a switch in any position and measure the resistance across two terminals on
the side. "ON" is where resistance is zero. Then rotate the switch so that DOWN is ON (UK
style).

Q: The picture and layout show a grounding screw next to the IEC plug, the chassis is not drilled
for one. Can I run the ground to the common star ground that the power transformer.
A: To meet electrical safety code, the mains ground must be connect by itself to the chassis. It is
best to drill a hole to connect the 120 V ground to a bolt that fastens to the chassis.
Don't run the 120 V ground to the common star ground.

Q: I assume that the shield is only attached to the pot; it is NOT connected to the tube socket?
A: Yes. Do not connect shield at both ends on the TMB volume pot OR input cables.

Q: For the impedance switch, do I use the 5 amp or 20 amp wiring? From the layout I would
guess the 5 Amp.
A: Use 5 A for the impedance switch. The amp is fused at 2A anyway, so 5 is plenty.

Q: The wire looks to be two basic sizes, "thin" and "thick". From the pictures, it looks like the
"thin" is used for the pot wiring and the "thick" is for the tube sockets. Is this correct?
A:
Use 20 Gauge solid for hook up to tubes;
Use 20 Gauge, twisted tightly for tube heater wiring;
Use 20 Gauge solid/stranded for hook up to pots/front panel; and
Use 18 gauge, stranded, 600v for power supply hook up - to transformers, rectifier, standby etc.
Tip: Re-use cut-offs from the transformers for power supply hook up.

Q: What should I use for the jumper wires on the back of the turret board?
A: Use the provided solid 20 ga or the stranded supplied for jumpers,

Q: For the input jacks:

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