GB for DC coupled B1 buffer with shunt PSUs

[jean-paul]

I have recently had 25V tantalums fry themselves with 20V applied. Two right in a row. They lasted a few minutes then fizzled. This was input of simple LM7805 circuit. Not on DCB1.
Uriah

Uriah, did nobody tell you that tantalums must be connected with the + to the positive supply

 

[Salas]

Plain 3mm 1.8Vf leds are perfectly OK.

 

[billyk]

Plain 3mm 1.8Vf leds are perfectly OK.

Worked fine for me! $.02 each

 

[cHoc]

For the LED's if 7mA is a little on the max of what we need, maybe the other suggestion i did earlier are a better choice from Mouser; 593-VAOL-3HCE4 has a typical Vf of 1.8v at 20mA.
Then we will have a better margin at the mA.

or just plain LED's from around the corner

 

[korben69]

Please check this one
Farnell : 1003205 - HLMP-K101

 

[Salas]

If it tends to bunch around 2V at its 20mA test current. it is very probable that it will offer enough around 1.7-1.8V at battery test 6-7mA area. Looks like a good led case to me. Is it 3mm?

 

[Salas]

Yes, it is.

 

[pchw]

If you are in US, these are quite suitable. I bought 3 bags of them some them ago. My 9V battery test showed 1.79V dropped.

 

[korben69]

Size doesn't matter...

 

[pchw]

If you are in US, these are quite suitable.

 

[udailey]

Uriah, did nobody tell you that tantalums must be connected with the + to the positive supply

Come on now! It was obvious they were not bipolar when I saw their long/short legs.
Uriah

 

[woodturner-fran]

Although I haven't done it - yet! - I believe those tants are quite spectacular when they go. Might have to sacrifice one to the gods just to see. Why the hell they marked the pos lead rather than the neg lead like they do on an electrolytic I'll never know.


Fran

 

[udailey]

A bit like a sparkler. It was only 1uF so no serious fireworks. A bit of it did hit me in the cheek. Took a few minutes of operating for it to go.

 

[Salas]

You need to do tubes. I see talent. Tubelab George needs an apprentice.

 

[udailey]

20V sparklers are fine. 350V sparklers are not probably going to be as friendly.
You are into tubes arent you Salas?
What are you running with your DCB1?
Uriah

 

[Ed LaFontaine]

Choose the VCT you want to work with and do a search.

For the USA, Looking for 25.2VCT provided this @ $5.25:

Unicorn Electronics - 25.2VCT 450MA Power Transformer

among others. There are candidates to be found @ 28VCT also.

 

[DualTriode]

Hello All,
I am new to this thread. This past Sunday I went to Burning Amp and came home with a nice new PCB in Hand.
This thread has lots of information to dig through. I have questions. Is there a recommended parts list (upgrades?)? How do I get on the list for the next buy of matched parts? Is there a summary somewhere that looks like assembly instructions?
Thank You
DT
All just for fun!

 

[Tea-Bag]

Hello All,
I am new to this thread. This past Sunday I went to Burning Amp and came home with a nice new PCB in Hand.
This thread has lots of information to dig through. I have questions. Is there a recommended parts list (upgrades?)? How do I get on the list for the next buy of matched parts? Is there a summary somewhere that looks like assembly instructions?
Thank You
DT
All just for fun!

DT, you received a proto board from the gb, your lucky in that you got one before most others. Some of the parts around the relay have changed. Scroll back not too far and Korben69 posted BOM 4.2, that's pretty accurate. on the other thread (building a symmertrical B1 buffer?) Ian444 posted assembly hints. I hope that helps. If you patient, a lot of people will be getting boards and going through the same process.

 

[grufti]

The 2SK170BL transistors are the only part that is a bit more difficult to source, but I just noticed that you list Sacramento as your location ... and it also just so happens that I have a few that I can share. All the rest is in stock at mouser, with the possible exception of fancy resistors for the audio path. partsconnexion is the best place to get those.

Send a PM to get in touch for the 2SK170 transistors. Which pcb did you get, hyp or mez?

 

[woodturner-fran]

Thats question I was going to ask - are we happy enough with the last version of the BOM posted?

I was going to go ahead and do my mouser order tonight or tomorrow night......

Fran