I had too much heat at reflector,it was 10A TO220.
So I changed into 35A bridge reflector.
Then I could bias correctly.
I turn it up and start listening music with bulb tester.
Ok no problem,then without bulb tester it sounds better.
But few seconds later, a smoke came out from R2 0.47ohm left channel.and R2 turned into black.
I'm getting better but still have problem.
So I changed into 35A bridge reflector.
Then I could bias correctly.
I turn it up and start listening music with bulb tester.
Ok no problem,then without bulb tester it sounds better.
But few seconds later, a smoke came out from R2 0.47ohm left channel.and R2 turned into black.
I'm getting better but still have problem.
0.5 V is not 0.5 A
0.5V is around 1A
Bias to 0.5A, that is about 0.25V across the source resistors.
0.5V is around 1A
Bias to 0.5A, that is about 0.25V across the source resistors.
I turn it up and start listening music with bulb tester.
Ok no problem,then without bulb tester it sounds better.
But few seconds later, a smoke came out from R2 0.47ohm left channel.and R2 turned into black.
.
Did you turn down the bias pots, then re-bias after removing the bulb tester? You must do this and let it settle (get up to temprature)
Sounds a lot of work, but it is vital to do this for long term stability.
Hum noticed Please help
My F6 is working. It sounds beautiful. To my years, the highs sound silkier than my Tube power amp. Really impressed.
Per 6L6 recomm
Initially, I was concerned how F6 would drive by 16 ohm altecs. Bias set at .575v, no issue... Altec is behaving well. Should I try to raise it little high?
And, B1 Nutube matches well with F6. These babies are here to stay.
One issue tho. I hear hum, audible from 8 to 10 feet away. I don't have a scope but it feels like the hum is well above 60hz. The power trans is relatively shilded well and it's far away from the input trans. So I wandering if the followings are the possible cause.
1. PSU
2. Pre
3. Cable
4. at 99db, my altecs are just too sensitive
any other lead?
Thanks
My F6 is working. It sounds beautiful. To my years, the highs sound silkier than my Tube power amp. Really impressed.
Per 6L6 recomm
1) Higher bias is better as long as you do not get the heatsinks too hot.
Initially, I was concerned how F6 would drive by 16 ohm altecs. Bias set at .575v, no issue... Altec is behaving well. Should I try to raise it little high?
And, B1 Nutube matches well with F6. These babies are here to stay.
One issue tho. I hear hum, audible from 8 to 10 feet away. I don't have a scope but it feels like the hum is well above 60hz. The power trans is relatively shilded well and it's far away from the input trans. So I wandering if the followings are the possible cause.
1. PSU
2. Pre
3. Cable
4. at 99db, my altecs are just too sensitive
any other lead?
Thanks
It's worth just measuring the AC value across your speaker terminals just to confirm it's not something higher than normal.
Thanks 2 picoDumbs
My psu cap value is 75000uf. I can expand it to 90000uf.
Would love to try cap multiplier. Any simple schematic suggestion? 😀
Please don't tempt me. I thought about changing them out... noooo not gonna do it!
Upgrade psu with more filtering or better yet cap multiplier
My psu cap value is 75000uf. I can expand it to 90000uf.
Would love to try cap multiplier. Any simple schematic suggestion? 😀
Your Altecs are sensitive
Please don't tempt me. I thought about changing them out... noooo not gonna do it!
will do! What an excellent suggestion!It's worth just measuring the AC value across your speaker terminals just to confirm it's not something higher than normal.
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Just first check with a multimeter that there isn't anything unusual happening at the output of the speaker terminals.
Just first check with a multimeter that there isn't anything unusual happening at the output of the speaker terminals.
A channel 0.042mv
B channel 0.033mv
Offset 0
When you say 75,000uF is that per rail or total?
per rail
So we will improve the psu
sounds good to me. should i add 15000uf per rail?
BTW, my fellow diyers. F6 sounds beautiful. I am loving it. thanks for your help!
It's 3am.
Can it wait till I wake up?
Hahahaha
Imagine if I was employed to do this, that bloody employer would get good value for money. I don't even bloody sleep, and if I do sleep I'm dreaming about this.
When I do a poo I get ideas too.
I'm always working.
Baaah Hahaha
Can it wait till I wake up?
Hahahaha
Imagine if I was employed to do this, that bloody employer would get good value for money. I don't even bloody sleep, and if I do sleep I'm dreaming about this.
When I do a poo I get ideas too.
I'm always working.
Baaah Hahaha
sounds good to me. should i add 15000uf per rail?
BTW, my fellow diyers. F6 sounds beautiful. I am loving it. thanks for your help!
No.
We will do much better than that.
Sorry! I did not realize that. It's 1pm here! 😀It's 3am.
Sweet dream! Let the thoughts of gentle papa take you to the dreamland. 1 little lamb...2 little lamb... 3 F12 pure class A no no not that one. Good night! thanks again! 😀
A channel 0.042mv
B channel 0.033mv
per rail
Can't sleep till you confirm this.
1) When you take this measurement are the speakers connected and do you hear the hum?
2) If you touch probes together for zero measurement, what measurement do you get?
If your multimeter is accurate, 33uV is very good actually. I wouldn't expect to hear hum that loud.
Are you sure it wasn't 0.33mV?
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