The new amp....
Hi Gauthier!!
Nice to ear from you!!
I feel happy for yours results....
Maybe you can send a email for the company that produces this wonderfull piece of high end telling your experiences...and your solutions!
I strongly fell that this hum is a grounding problem...but just in case try to disconect C3 temporarily that goes to the magic eye and see if it desapear...
I haven't find any specs of the 2C51 tube in my tube manual...(a rarity tube !!)...but i think that 2mA don't look to bad!
Thank you to ...because you have trust me...
Many voices here don´t see any problem in the pot position!
Regards
And looking forward for more news from you!
Hi Gauthier!!
Nice to ear from you!!
I feel happy for yours results....
Maybe you can send a email for the company that produces this wonderfull piece of high end telling your experiences...and your solutions!
I strongly fell that this hum is a grounding problem...but just in case try to disconect C3 temporarily that goes to the magic eye and see if it desapear...
I haven't find any specs of the 2C51 tube in my tube manual...(a rarity tube !!)...but i think that 2mA don't look to bad!
Thank you to ...because you have trust me...
Many voices here don´t see any problem in the pot position!
Regards
And looking forward for more news from you!
Hi Jorge,
Happy to read you again
About the noise, I already have removed C3 because his max voltage was 40V or something else. I alse have remove the EM80, and is a bit better.
It could be indeed a groung loop or something like that but its quite difficult to fix sich a think on a PCB.
Also, the heaters of V3 and V4 are feeded in AC. As the power comes in 5 wires in the same harness, the is maybe a cross talk also...
About the input tube or other exotic tubes, can i siggest you the use of TDSL :
http://www.duncanamps.com/tdslpe/
Finaly, i don't agree with the idea to send a mail to Dared. They are stupid, they can go to hell.
Rgrds and thanks again,
Gauthier
Happy to read you again
About the noise, I already have removed C3 because his max voltage was 40V or something else. I alse have remove the EM80, and is a bit better.
It could be indeed a groung loop or something like that but its quite difficult to fix sich a think on a PCB.
Also, the heaters of V3 and V4 are feeded in AC. As the power comes in 5 wires in the same harness, the is maybe a cross talk also...
About the input tube or other exotic tubes, can i siggest you the use of TDSL :
http://www.duncanamps.com/tdslpe/
Finaly, i don't agree with the idea to send a mail to Dared. They are stupid, they can go to hell.
Rgrds and thanks again,
Gauthier
the monobloc saga...
That's the reason i don't like monoblocs...
See you have to grounds in each monobloc conected together at the power suply...so when you conect the interconects as the CD as a comum ground...you build a hum loop...
Try to disconect the ground side of one of the interconects at one channel only...and see (listen) what hapen!!
That's the reason i don't like monoblocs...
See you have to grounds in each monobloc conected together at the power suply...so when you conect the interconects as the CD as a comum ground...you build a hum loop...
Try to disconect the ground side of one of the interconects at one channel only...and see (listen) what hapen!!
RE:the monobloc saga...
Hi,
What's not to like about monoblocks?
They offer superior stereo separation amongst other things, I use and have built for cistomers many monoblock designs, poweramps, preamps in separate chassis, dual mono PSus you name it.
Not a single customer ever experienced a hum problem....
To the best of my knowledge, there's not a single reason why a monoblock or dual mono design would be the cause of any hum.
Naturally some knowledge on grounding schemes helps, in fact proper grounding is one of the key factors in good design.
Cheers,
Hi,
What's not to like about monoblocks?
They offer superior stereo separation amongst other things, I use and have built for cistomers many monoblock designs, poweramps, preamps in separate chassis, dual mono PSus you name it.
Not a single customer ever experienced a hum problem....
To the best of my knowledge, there's not a single reason why a monoblock or dual mono design would be the cause of any hum.
Naturally some knowledge on grounding schemes helps, in fact proper grounding is one of the key factors in good design.
Cheers,
Hi you all,
I don't really know if monoblocs are best or not. Personaly, i just see that it cause problems to me. It's indeed better whe interupting on of both groung in the cinch...
The is still a hum when i increase the volume, but lower. To investigate again.
THanks to Jorge for his advice...
Gauthier
I don't really know if monoblocs are best or not. Personaly, i just see that it cause problems to me. It's indeed better whe interupting on of both groung in the cinch...
The is still a hum when i increase the volume, but lower. To investigate again.
THanks to Jorge for his advice...
Gauthier
Happy !
Hi !
I have done the following modifications :
*interupted de ground on the input of one chanel
*moved the ground power supply connection from the top edge to a point near the preamp where all the grounds seem to be connected in star
The result is incredibly better in comparision to the begining.
Thanks to all,
Gauthier
Hi !
I have done the following modifications :
*interupted de ground on the input of one chanel
*moved the ground power supply connection from the top edge to a point near the preamp where all the grounds seem to be connected in star
The result is incredibly better in comparision to the begining.
Thanks to all,
Gauthier
Phasesplitter issue
Yea, it is a poor design anyway.
It looks to me, that the designer mixed several
peaces of schematics. The 2C51 is the wrong
tube in the phasesplitter, C4 and R6 arex'nt necessary, and the cathodes are connected to nowhere.
BTW: the not connected cathodes remebering me to an unusual schematic with the ECLL80.
They where groundet with the ping for the
triode section, floating around in the schematic ...
Holm
Yea, it is a poor design anyway.
It looks to me, that the designer mixed several
peaces of schematics. The 2C51 is the wrong
tube in the phasesplitter, C4 and R6 arex'nt necessary, and the cathodes are connected to nowhere.
BTW: the not connected cathodes remebering me to an unusual schematic with the ECLL80.
They where groundet with the ping for the
triode section, floating around in the schematic ...
Holm
An EL90 tube cannot have nine pins - the '9*' designation at the end means that it was designed for a B7G base - seven pins only. If your tubes have this designation they have been wrongly labelled.
As for changing them for EL84s if the pin connections are the same - I doubt if you would do any damage to the amp, especially as it seemed to be designed for EL41s anyway. You might have to experiment with bias resistors and suchlike for optimum operation.
As for changing them for EL84s if the pin connections are the same - I doubt if you would do any damage to the amp, especially as it seemed to be designed for EL41s anyway. You might have to experiment with bias resistors and suchlike for optimum operation.
EL90 for shure...
Hi Bournville,
I have checked it again. THey are well labeled EL90 and have 9 pins.
Again a mystery of the chinese electronic...
If you check on the shematics, you will see as alternate outupt tube, EL41 with 9 pins. It doesn't exist neither...
Anyway, i will check inside to find the tube pinout...
Hi Bournville,
I have checked it again. THey are well labeled EL90 and have 9 pins.
Again a mystery of the chinese electronic...
If you check on the shematics, you will see as alternate outupt tube, EL41 with 9 pins. It doesn't exist neither...
Anyway, i will check inside to find the tube pinout...
...The EL41 is a eight pin tube, the '4*' designation meaning it has a B8A base - I assumed the errors on the original circuit were typographical errors. The EL90 designation is definately wrong if that tube has nine pins. It could be a mis-labelled EL84.
The original schematic does give EL84s as an alternative - why not try them if it does not mean too many circuit alterations?
The original schematic does give EL84s as an alternative - why not try them if it does not mean too many circuit alterations?
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