@Alexontherocks: What are source are you using for your amp? Laptop?
I've found that the DCPP works with my iPod as a source but it has to be cranked to 10 for good output. I get the best result when I use a preamp or a stronger source like a discrete cd player.
I've found that the DCPP works with my iPod as a source but it has to be cranked to 10 for good output. I get the best result when I use a preamp or a stronger source like a discrete cd player.
I have used my ipod, a cell phone, my own laptop all maxed out but the volume on the amp is nowhere near loud as I would expect.
Music quality is excellent though.
What kind of measurments must I perform to debug the board? Is there any obvious mistake in assembly I may have made?
Thanks for the support.
Music quality is excellent though.
What kind of measurments must I perform to debug the board? Is there any obvious mistake in assembly I may have made?
Thanks for the support.
P.s. I am using 6JN6 tubes...if the problem is overall gain (I doubt it...something is clearly wrong) is there a direct valve replacement (ie: plug and play?)
Thanks!
Thanks!
Alex, it's unclear from your description whether you have a power shortage (i.e., the amp clips before reaching 15 watts) or gain shortage (with the source maxed, the amp isn't clipping but the volume is low). Could you please clarify?
The amp does not clip infact cranking the ipod output does not produce any discernible distortion.
Basically maxing out the source the volume is acceptable (on the lower side) but very sharp and free of distortion.
I believe the overall gain is lower than expected.
Basically maxing out the source the volume is acceptable (on the lower side) but very sharp and free of distortion.
I believe the overall gain is lower than expected.
The amp does not clip infact cranking the ipod output does not produce any discernible distortion.
Basically maxing out the source the volume is acceptable (on the lower side) but very sharp and free of distortion.
I believe the overall gain is lower than expected.
Basically maxing out the source the volume is acceptable (on the lower side) but very sharp and free of distortion.
I believe the overall gain is lower than expected.
Gain problem
I also built a totaly stock amp with the Edcors and 6JN6's. The only deviation is a 50K PEC pot and I bypassed the coupling caps with Russian teflons. Although not built for them, I am currently listening to them through Proac 2.5's. If I remember correctly this speaker is 87db, so not too efficient. My source is a CD player and the room size is not too large. My normal volume is typically between 12 and 2 oclock depending on the CD and I like my music somewhat loud. I am fairly confident that I would be driven from the room before clipping. So the answer to your question: (is this normal) I think not.
Paul
I also built a totaly stock amp with the Edcors and 6JN6's. The only deviation is a 50K PEC pot and I bypassed the coupling caps with Russian teflons. Although not built for them, I am currently listening to them through Proac 2.5's. If I remember correctly this speaker is 87db, so not too efficient. My source is a CD player and the room size is not too large. My normal volume is typically between 12 and 2 oclock depending on the CD and I like my music somewhat loud. I am fairly confident that I would be driven from the room before clipping. So the answer to your question: (is this normal) I think not.
Paul
I don't think it is normal either. The first board I built was stock except for minor parts substitutions based on junk box availability. The amp would definitely hit clipping when fed from a CD player on most CD's.
Check over your board to make sure that all of the resistors are the correct value.
iPod only Puts out ~1volt vs cdp's 2 volts. You definitely will not drive the amp to clipping.
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Hi Nightanole
Had a bit of a look on the net for the 6GF5 datasheet??? No joy
Do you or anyone else have a copy?
Cheers
Had a bit of a look on the net for the 6GF5 datasheet??? No joy
Do you or anyone else have a copy?
Cheers
just checked the resistor values and everything is fine....
I believe the problem is the source....I will try with a cd player and see what happens. Aside from this issure the amp works flawlessly....excellent sound.
The power transformer becomes warm (can keep my hand on it) but everything else is in order.
I might actually build a valve preamp...suggestions? 😉
I believe the problem is the source....I will try with a cd player and see what happens. Aside from this issure the amp works flawlessly....excellent sound.
The power transformer becomes warm (can keep my hand on it) but everything else is in order.
I might actually build a valve preamp...suggestions? 😉
Why yes, yes I do...🙂 A grounded cathode 12B4A with a CCS plate load will do well. Built the CCS from depletion-mode MOSFET's and use the mu output for minimum output impedance. It seems your source level is low by a factor of 2 or 3, so mu of the 12B4 should take care of it well. Consider also type 6AH4 with a mu of 8. either of these can be done with a B+ of ~200V with plate voltage around 120-140( with the rest left over as lots of headroom ).
cheers,
Douglas
Thanks!
I actually could have a matisse fantasy board for around 10 euros...the gain per stage is 30db.
seems like a good candidate...
I actually could have a matisse fantasy board for around 10 euros...the gain per stage is 30db.
seems like a good candidate...