[mybud]

FWIW I’ve just built the selfsame circuit, but noticed that it doesn’t seem to work if D1 is not connected.

Maybe try this if it still fails to work after you’ve replaced the BJTs with FETs.

@Billy: 2 questions if I may

1. 5459s are fairly easy to obtain here (South Africa), unlike 5457s and 5458s, which are scarcer than hen’s teeth. However they don’t always seem to be a comfortable straight swap. Some (unwanted) distortion creeps in, or so it appears to my ears. Do they behave similarly to 5457s, or should one adjust bias resistors or what have you? BTW I’m not assuming there’s a straightforward answer to this one.

2. For some unknown reason, on my build the rate pot works the other way round (i.e CW gets slower). I’ve double checked the installation and it looks ok. Just wanted to check that this is intended? If so, well and good and I haven’t entirely lost the plot.

Thanks again and hope this doesn’t entirely Muddy the Waters (pun intended). Best, Marc

 

 

[mybud]

Thanks again, wilkie1. Problem solved.

[mybud]

Hi all: Thought I’d provide some feedback (no unintended) on my adventures with the switch. I tried Sasan’s mod first, flipping the wires along the vertical. Please see above. This makes sense because the switching pattern (in the middle position) is asymmetrical. That was my a-ha moment!

But sorry to say same effect, no sound in the middle position. I then rewired it as per Barry’s diagram above. Same story. It crossed my mind that an alternative arrangement might be to use an ordinary DPDT to give the option of choosing between normal and brite channels, but not both, but now I’m kind of determined to resolve this particular option (i.e. all options available).

I then redeployed my trusty Fluke DMM and lo and behold, the switching pattern for this particular one (MTS-2 from Tayda) appears to be different, as follows:

1                   4

2                   5

3                   6

Centre position (1 connects to 2, 5 to 6)

Switch up (2 connects to 3, 5 to 6)

Switch down (1 connects to 2, 4 to 5)

If anyone has the patience to help with us, it’ll be greatly appreciated. I’m afraid it has me beat; I can’t get two options to work but not three.

Best to all and many thanks in advance, Marc

[mybud]

Greetings all: Just built the Sunn-T, and it sounds great. Mild settings are especially useful to my ears.

However, I’ve run into the same switching issue as Sasan (earlier posts regarding non-functioning centre position). I did test the wiring with a DMM and thought it (the switch, that is) corresponded exactly with the build document layout, but no. No sound in the centre position and other options working fine. I could do this by hit and miss but don’t want to mess it up. So could anyone kindly advise a step-by-step solution to some my problem?

@Sasan: I seem to recall that you solved this by swapping some wires? Would you mind giving me a bit more detail?

Best to all and thanks for a great forum (and circuit).

Marc (South Africa)

 

[Author]

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