jose

Do I need use any resistance on the Buffer output?

Have you tried to download the BIAS?

If you have 3.3volt, something is wrong.

Yesterday I tested my pcb's and they seem to work correctly. Offset on un/bal output is 0mVolt (with servo). With buffer I measure an offset of 8mVolt on the output in each one. It's right? I'm using OP27.

EH 6CA7 and Tung sol EL34 maybe?

Happy Birthday

Change of pads and rotor.

Thanks Michael!!! I have inventory of bought devices but I prefer the KSA1156 too. It's more easily to fixed. I'm waiting for trafos Edit. I saw you answer

Disastrous management

million per year, it's a lot of money for a small business...

José James

Before touching anything, I would first change the resistance of 500 Ohm. About offset, In my case the Offset was influenced by the BIAS too high and by the THAT340.

Yes, you can change r500 (next to Trimpot) for other from 620 Ohm to 1K.

Thanks Birgir but both are very difficult to find too. I´m working on my Megatron and checking the threadt I found references to STN9630 and KSA1156 but I would like to be secure.

To replace the 2SA1968, which is the best option? The STN9360 or the KSA1156? *STN9630 is SMD (I have boards for adapt this to TO220). *KSA1156 The Pins are the opposite, you just have to rotate it.

Not always ... this winter has been hard. Many storms, strong winds... we have had up to snow for a few months Fortunately, climate change is a lie... or so they say

If it´s posible, I like blue

Spring is here....[emoji41]

good question

I measured all my BC556/546 BTA stock: hfe from 299 to 416 but the most abundant value is in the fork from 320 to 380. I don´t know whether to do it with these values. I have 100 BC546CTA bought in Mouser too and today I found a guy who bought him another 100 units of the BC556C ... I hope to be lucky.

I buy all my sand on Mouser and They say that for example On/Fairchild BC556BTA grade has a measure of HFE/450. I have around 200 eas on my warehouse I need some time for measure some units but I guess that they don't lie... or this I would like to believe. Edit: I'm seeing that I have some KSA992FTA/KSC1845FTA but yes, Pars is right; It's a shame they have different pinout.

Finally, can BTAs work?

John Pizzarelli trio "live at birdland"

I bought 35 of each one for this proyect. I like to have reserve inventory.

Happy Birthday!