Sorry to keep your head spinning, Hugh - but if a Mosfet is not blown ... what does gate to source measure?
Thanks,
Hugh, please read comments of today in the class A headphone amp, some members need your insight.
Hugh,
Sorry about the confusion. All this talk about different trafo voltage was started in the case that I wanted to change to a CRC type PSU, which I do not. My plan is to use the Antek trafo's I have which are the ones that measure 25V secondaries. The SLB's should have no problem with the 25V input secondaries, as xrk971 has used higher V values when verifying the SLB works.
I removed all the SLB's STP110N8F6 MFet's on both SLB's and tested the gate's to source. All of them except one measure OL on the DMM ohms scale. The bad one measures 166 ohms. So I need a new one.
What is your's and X's idea's about running the AN39 with a 31V input from the SLB's. Could I use at reduced bias current? If this is entirely not possible, then what can I do to reduce the voltage before entering the amplifier (ie: diodes, ldo reg, etc) so that I do not have to buy new trafo's (sorry, I am cheap) 😉 .
Thanks for the help,
MM
Sorry about the confusion. All this talk about different trafo voltage was started in the case that I wanted to change to a CRC type PSU, which I do not. My plan is to use the Antek trafo's I have which are the ones that measure 25V secondaries. The SLB's should have no problem with the 25V input secondaries, as xrk971 has used higher V values when verifying the SLB works.
I removed all the SLB's STP110N8F6 MFet's on both SLB's and tested the gate's to source. All of them except one measure OL on the DMM ohms scale. The bad one measures 166 ohms. So I need a new one.
What is your's and X's idea's about running the AN39 with a 31V input from the SLB's. Could I use at reduced bias current? If this is entirely not possible, then what can I do to reduce the voltage before entering the amplifier (ie: diodes, ldo reg, etc) so that I do not have to buy new trafo's (sorry, I am cheap) 😉 .
Thanks for the help,
MM
Kokanee, of course you can do that, in fact reducing the bias will get the sane result while there is power supply headroom maybe less ripple. Not cheap maybe smart
With a single ended class A it will do what it is supposed to do until it is current limited. It won't distort like class AB the sound will simply fall apart and become rubbish, That is how you know you are expecting too much. The number of times that you will use this amp above ten watts in your life will be few. I think a 40W class A amp with reasonably efficient speakers border on the ridiculous. I don't think there is physical proof of this but in my experience a SE amp sounds louder than an equivalent class AB. maybe it has to do with the higher harmonic content
I have removed all the components ( except for the 15K uf and 1K uf caps) from both of the dual rail SLB's and will be performing test's on each components before reinstalling.
I have also found a work around for the Antek 4224 trafo's. I will use these on a PeeCeeBee V4H at a reduced power output than what I was planning.
I will be ordering 2 x 300VA/22V trafo's for the AN project.
All is well, thank you to all for their insights and help.
MM
I have also found a work around for the Antek 4224 trafo's. I will use these on a PeeCeeBee V4H at a reduced power output than what I was planning.
I will be ordering 2 x 300VA/22V trafo's for the AN project.
All is well, thank you to all for their insights and help.
MM
greetings! I’ve been working steady on the an39. I have gotten the soft start and the slb to successfully work. Now I am finishing up wiring up the amp boards to fire up. My worry is that I’m not understanding the wiring. Can someone post a pic of there board hooked up to an SLB? I’m having a bit of a lack of confidence as to where the + - wires connect on the input and output. Also, just want to make sure I’m connected correctly. Thanks for all the help everyone!
Hello Bmm,
If you are using one dual rail slb, then the pic below from post a#2962 should help you out. Please see the attached wiring diagrams attached. These are from post #3124. Hopefully these will help you.
If you are using one dual rail slb, then the pic below from post a#2962 should help you out. Please see the attached wiring diagrams attached. These are from post #3124. Hopefully these will help you.
I measured one side which seems to be working correctly. On the NPN and pnp G=21v, S= 26. On the other othere side I’m getting NPN G=9v, S=13.5v. PNP G=34v, S= 39v.
Some first tests with the two-channel operation. I need to decide the bias current setting at 2.2A or 2.65A. The first impressions analytic amp deep extended bass with a big 3Dstage .
Hi,
Blowmymind@, Sorry, I can't help you, I wish I had more knowledge ;-)
Nikos@,
Thank you for your first impressions. What differences do you notice in terms of sound with the different values of the bias current?
Also to comment on the pity of the fire that is raging at the gates of Athens...a disgrace.
Regards
Blowmymind@, Sorry, I can't help you, I wish I had more knowledge ;-)
Nikos@,
Thank you for your first impressions. What differences do you notice in terms of sound with the different values of the bias current?
Also to comment on the pity of the fire that is raging at the gates of Athens...a disgrace.
Regards
Υ
Small difference.....i repeat the test.
About Greece.....hmmm what can is say....
The Greeks are experiencing the worst here for two decades..Economic squeeze, their governments have sold off almost everything for the benefit of others except the Greeks. Burned land for various private purposes. Photovoltaic wind turbines ....High cost of food very small salarys. But this is how Greece has always been subordinate to others.Let's not have a complaint, but we vote them and that's what we enjoy. We live in a virtual economic reality......
Τhanks for your comments.
Small difference.....i repeat the test.
About Greece.....hmmm what can is say....
The Greeks are experiencing the worst here for two decades..Economic squeeze, their governments have sold off almost everything for the benefit of others except the Greeks. Burned land for various private purposes. Photovoltaic wind turbines ....High cost of food very small salarys. But this is how Greece has always been subordinate to others.Let's not have a complaint, but we vote them and that's what we enjoy. We live in a virtual economic reality......
I would so that more bias on the AN (2.65A) ensures that very high amplitude bass notes will not be clipped when driving 4R loads.
Greece is also experiencing the falling standard of living across the entire western world; it is to some extent driven by failing industry, increasing importation (particularly from China), a democratic malaise and the large movements of refugees from failed states through Europe.
Much of this is also the result of the demands of the population, the political populism of the democratic countries, and the transfer of wealth from the West to the East.
What to be done? Hell, I don't know........
HD
Greece is also experiencing the falling standard of living across the entire western world; it is to some extent driven by failing industry, increasing importation (particularly from China), a democratic malaise and the large movements of refugees from failed states through Europe.
Much of this is also the result of the demands of the population, the political populism of the democratic countries, and the transfer of wealth from the West to the East.
What to be done? Hell, I don't know........
HD
That's exactly how I feel about my country! I feel even sorrier for our children, because we old ones will soon be passing away.
But Nikos,
a big compliment on your amplifier setup, I like it very much.
Can we hear Anna Ternheim in the background?
regards,
HBt.