Mine has 6.2v and 3.3r in R7 R8 , as the forum suggested.
Haven't pulled the boards yet to start checking. Life gets in line and steals my DIY time. Lol
As I remember, it did take a ridiculous amount of turning befor anything happened. Finally, numbers began to register.
Russellc
If you do have 3.3 instead of 3.3K then there could be the problem. This is a common mistake we all have made, mistakenly put a set value instead of a K value. I honestly do remember the value recommended with the 6.2 Zener. Mine has the 9.1 zeners and 10K resistors. You will need to go back in this thread to see the recommended value unless someone remembers and responds.
3.3R is way too low and you will get a a large current through the zener.
Perhaps the zener is damaged? Come to think of it, the 3.3R may not
be doing too well either.
I would replace the zener and use a 3.3K resistor.
When you power up, you should measure about 6.2V (or whatever voltage
zener you use) across the zener diode.
Cheers,
Dennis
Perhaps the zener is damaged? Come to think of it, the 3.3R may not
be doing too well either.
I would replace the zener and use a 3.3K resistor.
When you power up, you should measure about 6.2V (or whatever voltage
zener you use) across the zener diode.
Cheers,
Dennis
Thanks I will recheck the values and adjust accordingly. That's a great help as I think I messed that one up.
Since you've played around with the pots, I suggest you set them back to
their mid point positions before powering up. (You may have to count the
number of turns.) Assuming you are using 6.2V zeners at midpoints you
shouldn't encounter the problem of the bias being to high at startup.
Cheers,
Dennis
their mid point positions before powering up. (You may have to count the
number of turns.) Assuming you are using 6.2V zeners at midpoints you
shouldn't encounter the problem of the bias being to high at startup.
Cheers,
Dennis
This is good bad news. As I said we all have done this before. I usually catch it before installing because I always test each and every resistor with a checker before installing. I think now you are on the way to music. I would also replace the zeners at the same time while you have the boards out. If a part is cheap I always order some spares.
As my opinion, it not suits that the power inlets has emi filter, for class A amp. May be ok. for dacs, preamps, class d amp.Silly question reallyCan / should I use this thing (rated at 3a)?
New but found in a drawer, or is a simple 2$ Chinese IEC plug with switch and fuse a better choice?
Sorry.. had a heck of a time getting even this fuzzy photo of it.
Changed the 3.3r to 3k3 and changed the zener too.
Bias up smoothly and plays wonderfully. So excited and happy.
Thank you guys for the help. I'll look forward to making more diy audio equipment.
Changed the 3.3r to 3k3 and changed the zener too.
Bias up smoothly and plays wonderfully. So excited and happy.
Thank you guys for the help. I'll look forward to making more diy audio equipment.
Great news.
diyAudio - Tea-Bag tried Cinemag and Onetics.
Lundahl LL1527 could be one very good alternative, but as everything it too requires some adjustment to the surrounding components, like gate resistors and so on...
Your tests were with the LL1527, correct? I have a pair of the LL1591 (touted as just an LL1527 without mu-metal shield) which I would like to try. I need to look for your circuit again to check what changes were necessary.
The Cinemag CMOQ-4H has been used by Tea-Bag and others.
