Finally got a chance to hook it up last night, sounds great! No noise from the power supply which doesn't surprise me since I use this PS for my guitar pedals. This thing can even drive speakers, not very loud but it can do it.
Okay, in the article it say's "Next check for DC offset at the headphone output. The DC offset should be less than 10 mV. I measured 8 mV max, typical 3 mV."
This is between the negative of the 470uF cap and what? Main ground maybe?
Here's the article:
NP-100v12: DIY 12AU7 (ECC82) Tube / IRF510 MOSFET Headphone Amplifier
Thanks for all the help, glad it worked right after building it.
Glenn
Okay, in the article it say's "Next check for DC offset at the headphone output. The DC offset should be less than 10 mV. I measured 8 mV max, typical 3 mV."
This is between the negative of the 470uF cap and what? Main ground maybe?
Here's the article:
NP-100v12: DIY 12AU7 (ECC82) Tube / IRF510 MOSFET Headphone Amplifier
Thanks for all the help, glad it worked right after building it.
Glenn
Hi,
Surprising isn't it! ECC82 running on 12V.
I believe the offset is measured to ground. I would not worry to much if its within spec!
Any thoughts on the build?
I found it fun, because the faults can be found without HT worries and it does present some unusual problems.
Well you have your tube section now you want a minature power section.
Any thoughts regards chips etc you might use. Or are you going to try 12V tube power section. Mini Watt comes to mind!
Regards
M. Gregg
Surprising isn't it! ECC82 running on 12V.
I believe the offset is measured to ground. I would not worry to much if its within spec!
Any thoughts on the build?
I found it fun, because the faults can be found without HT worries and it does present some unusual problems.
Well you have your tube section now you want a minature power section.
Any thoughts regards chips etc you might use. Or are you going to try 12V tube power section. Mini Watt comes to mind!
Regards
M. Gregg
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Yes, I didn't think it would sound as good as it does, very nice! I've been trying to read through the support forum for this build. I've read that it does take some time to allow the circuit to settle-in. I'll have to keep checking the bias to make sure it's 1/2 the supply.
I'm interested in the delay to prevent the popping. The 555 timer looks very simple, and you can adjust the delay time.
I haven't decided on the power amp section yet. I've been looking at some of the chipamp web sites for ideas, like the LM3886 "Gainclone". Now you have me curious, what's a "Mini watt"??
I'm going to put a switch on this build so I can select between the headphone jack and a set of RCA jacks on the back. I also have a set of RCA jacks for the input. I've seen 12AU7 amps like this on the auction site that have this feature. I suppose it's so you can use it as a preamp. They only have a switch for the output, so I assume both inputs (headphone and RCA) are connected all the time.
Thanks
Glenn
I'm interested in the delay to prevent the popping. The 555 timer looks very simple, and you can adjust the delay time.
I haven't decided on the power amp section yet. I've been looking at some of the chipamp web sites for ideas, like the LM3886 "Gainclone". Now you have me curious, what's a "Mini watt"??
I'm going to put a switch on this build so I can select between the headphone jack and a set of RCA jacks on the back. I also have a set of RCA jacks for the input. I've seen 12AU7 amps like this on the auction site that have this feature. I suppose it's so you can use it as a preamp. They only have a switch for the output, so I assume both inputs (headphone and RCA) are connected all the time.
Thanks
Glenn
I think you need a "power follower" ,not a high sensibility amp (like most of amps are: they reach full power with 0.3-1,5 V at the input ).
The output to the headphone contains voltage AND current ,but current usually don't happen in line level . So there is some added distortion from your headphone amp
or line driver that enters into another amplifier stage . Power follower may be very easy to build ...but since it works in class A the current request from the supply may be relevant ,
about 1 A for 10 W output.
The output to the headphone contains voltage AND current ,but current usually don't happen in line level . So there is some added distortion from your headphone amp
or line driver that enters into another amplifier stage . Power follower may be very easy to build ...but since it works in class A the current request from the supply may be relevant ,
about 1 A for 10 W output.
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Hi,
I used a Vellman 15 + 15 Watt (30 Watt) module. Makes a good mini system. When run with this it sounds quite nice!
The Mini Watt is here
Amplifiers
I would not use this, the power out is low. However I have been thinking of the idea of power tubes running on low volts! It does interest me! Just like the 82 running on 12V. I have not done anything as yet I have another project on the go!
I like to experiment!
Regards
M. Gregg
I used a Vellman 15 + 15 Watt (30 Watt) module. Makes a good mini system. When run with this it sounds quite nice!
The Mini Watt is here
Amplifiers
I would not use this, the power out is low. However I have been thinking of the idea of power tubes running on low volts! It does interest me! Just like the 82 running on 12V. I have not done anything as yet I have another project on the go!
I like to experiment!
Regards
M. Gregg
Yes its that one!
Please check the AC requirements are 12 + 12 so its not a single supply.
However it is quite good!
Regards
M. Gregg
Okay, my DC offset between the headphone output ground and the power input ground is 15mV. 10mV is specified as max., am I supposed to be measuring maybe the output L or R of the headphone out to power ground? Is this bad/damaging to have this high of an offset?
Any suggestions?
Sound good even with this issue!
Glenn
Any suggestions?
Sound good even with this issue!
Glenn
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