It is better to remove attenuator and do adjust the gain resistance
adjust your source playback level to 75 percent from it's maximum output volume.
Replace the gain resistance by a trimpot.... use 1K in series with 2K or 2K2 trimpot (the one you have available)
Them play music you know as very loud...some musics are not loud, or have "pianissimo" moments where the music is low in volume....so find some music that is loud and play it at 75 percent of the maximum playback volume (I hope you're not using Ipod..as it needs the headphone to filter the output...not good to plug directly into power amplifiers... the headphone coil makes part of the output filter... so it is good with earphone and bad without earphone).
If you have installed input potentiometer into your power amplifier, then turn it full clockwise, or, to increase the volume to the maximum to the power amplifier (if have assembled volume pot wrong way)
Now tweak your gain trimpot till distortion starts... clipping starts... you listen the sound of clipping...but be sure the clipping comes from the amplifier..sometimes the distortion comes from the speaker...this way the solution is to install 8 ohms array of resistances into the output to have good dissipation and to pick signal from another resistance to the speaker to monitoring...i will produce and attach a schematic about that.
Made the adjustment, them remove the trimpot plus the series resistance and measure outside the pcboard..... now install a fixed resistance with this value you found..if needed use two resistances in series to match the value you have measured.
I hope i was clear enougth.
Please...attach pictures from your amplifier....was fine to see the motorized tricicle, but amplifier pictures are more important to uncle charlie.
regards,
Carlos
adjust your source playback level to 75 percent from it's maximum output volume.
Replace the gain resistance by a trimpot.... use 1K in series with 2K or 2K2 trimpot (the one you have available)
Them play music you know as very loud...some musics are not loud, or have "pianissimo" moments where the music is low in volume....so find some music that is loud and play it at 75 percent of the maximum playback volume (I hope you're not using Ipod..as it needs the headphone to filter the output...not good to plug directly into power amplifiers... the headphone coil makes part of the output filter... so it is good with earphone and bad without earphone).
If you have installed input potentiometer into your power amplifier, then turn it full clockwise, or, to increase the volume to the maximum to the power amplifier (if have assembled volume pot wrong way)
Now tweak your gain trimpot till distortion starts... clipping starts... you listen the sound of clipping...but be sure the clipping comes from the amplifier..sometimes the distortion comes from the speaker...this way the solution is to install 8 ohms array of resistances into the output to have good dissipation and to pick signal from another resistance to the speaker to monitoring...i will produce and attach a schematic about that.
Made the adjustment, them remove the trimpot plus the series resistance and measure outside the pcboard..... now install a fixed resistance with this value you found..if needed use two resistances in series to match the value you have measured.
I hope i was clear enougth.
Please...attach pictures from your amplifier....was fine to see the motorized tricicle, but amplifier pictures are more important to uncle charlie.
regards,
Carlos
Attachments
Attachments
Enclosure just waiting to have something assembled inside
This one will have amplifiers inside, volume control and analogic power metering devices included.
Also will have four supplies inside:
63 plus 63 volts
35 plus 35 volts
20 plus 20 volts
12 plus 12 volts
An auxiliary adjustable power supply..symetrical and voltage adjustable.
A 220 VAC to 110 VAC...a step down transformer used.
Output sockets to 220 and 110 volts.
RCA connections for amplifier audio entering...speaker connector to speaker output and some RCA connectors will be the supply output to external amplifiers.
regards,
Carlos
This one will have amplifiers inside, volume control and analogic power metering devices included.
Also will have four supplies inside:
63 plus 63 volts
35 plus 35 volts
20 plus 20 volts
12 plus 12 volts
An auxiliary adjustable power supply..symetrical and voltage adjustable.
A 220 VAC to 110 VAC...a step down transformer used.
Output sockets to 220 and 110 volts.
RCA connections for amplifier audio entering...speaker connector to speaker output and some RCA connectors will be the supply output to external amplifiers.
regards,
Carlos
Attachments
HQ.... high quality video from April pictures posted into youtube
I'll be honored with your visit.
http://www.youtube.com/watch?v=_cBIbkbW_FE
regards,
Carlos
I'll be honored with your visit.
http://www.youtube.com/watch?v=_cBIbkbW_FE
regards,
Carlos
Now am having scratchy / noisy sound at every time turn the volume up or down and funny sound when turn the amp off
something like Zeeeeeeeek , for two seconds .
could be dust or something with the volume knob who causing that noise and about the Zeeeeeek , I think the PSU ...
something .
any help ?
something like Zeeeeeeeek , for two seconds .
could be dust or something with the volume knob who causing that noise and about the Zeeeeeek , I think the PSU ...
something .
any help ?
Attachments
Increase C14 value... try a 56 or 68pf capacitor there
If your case is wooden made..then you have a problem man!
Try to ground the potentiometer metalic back case..soldering a wire and run that wire to the transformers center tap..both transformer center tap must be connected one each other..the heatsink must be grounded too.... transistors (both) must be insulated from the heatsink...sometime you need to run a wire from the transformer metalic case too.... having not the metalic chassis you gonna have some problems and some special attention must be applied to grounding points.
Those two small heatsinks you are using are upside down.. also you have undersized heatsinks...you may have burned power transistors because of that.
Good luck.
regards,
Carlos
If your case is wooden made..then you have a problem man!
Try to ground the potentiometer metalic back case..soldering a wire and run that wire to the transformers center tap..both transformer center tap must be connected one each other..the heatsink must be grounded too.... transistors (both) must be insulated from the heatsink...sometime you need to run a wire from the transformer metalic case too.... having not the metalic chassis you gonna have some problems and some special attention must be applied to grounding points.
Those two small heatsinks you are using are upside down.. also you have undersized heatsinks...you may have burned power transistors because of that.
Good luck.
regards,
Carlos
Attachments
I understand that grounding is an imporatnt case .
the heastsink , yes it is small to handle the amp but am rnuning fan to keep it cool.
Did play the amp for 2 hours and I got little heat at the sink .
I used canned compressed air and at the volume knob and the scratchy noise gone .
about the Zeeeeek sound , was a bad capacitor . Got it replace .
I will wire from the volume knobe body to the ground and the heatsink to the ground , too .
thank you
Carlos , youtube is blocked here but I can do fool my ISP and get that website , but that last video wsant there ???
Any way , thank you .
still one thing mentioned to you in my other posts here that the LED at the positive rail turn off very fast than the one on negative rail . I think one of the big capacitor disharge faster than the other one , could be that ?
the heastsink , yes it is small to handle the amp but am rnuning fan to keep it cool.
Did play the amp for 2 hours and I got little heat at the sink .
I used canned compressed air and at the volume knob and the scratchy noise gone .
about the Zeeeeek sound , was a bad capacitor . Got it replace .
I will wire from the volume knobe body to the ground and the heatsink to the ground , too .
thank you
Carlos , youtube is blocked here but I can do fool my ISP and get that website , but that last video wsant there ???
Any way , thank you .
still one thing mentioned to you in my other posts here that the LED at the positive rail turn off very fast than the one on negative rail . I think one of the big capacitor disharge faster than the other one , could be that ?
Can be the capacitor defective, the resistances that feed the zener or other problems
I do not know..this is something you must explore.
Change your capacitors.... the negative one goes the the supply positive side...and the other do the oposite... also change leds..to see if they have something related the problem.
Also rectifiers maybe...do not know...you have to check parts to see what's going on.
I am glad you found something wrong..go ahead searching for bugs.
regards,
Carlos
last videos published into youtube:
http://www.youtube.com/watch?v=6nh85mMARZQ
http://www.youtube.com/watch?v=_cBIbkbW_FE
this second one is the last one..and has better image quality (HQ)
........................................................................
I am having lunch... collard green and sausage (banger)... olive oil from Greece, salt and garlic... grape juice (not wine!)
I do not know..this is something you must explore.
Change your capacitors.... the negative one goes the the supply positive side...and the other do the oposite... also change leds..to see if they have something related the problem.
Also rectifiers maybe...do not know...you have to check parts to see what's going on.
I am glad you found something wrong..go ahead searching for bugs.
regards,
Carlos
last videos published into youtube:
http://www.youtube.com/watch?v=6nh85mMARZQ
http://www.youtube.com/watch?v=_cBIbkbW_FE
this second one is the last one..and has better image quality (HQ)
........................................................................
I am having lunch... collard green and sausage (banger)... olive oil from Greece, salt and garlic... grape juice (not wine!)
An externally hosted image should be here but it was not working when we last tested it.
Yes... into stand by mode there are more consumption into the positive rail
it is just 20 percent more if you adjust to 60 miliamps into the positive rail...the negative rail will have only 50 miliamps of power consumption.
Observing the discharge without audio into the input for sure the positive led will be off in advance related the negative Led.
But if you switch off having audio into the input...well... this way they will go off at same time as this difference will be not significant face the much more energy will flow both rails.
regards,
Carlos
it is just 20 percent more if you adjust to 60 miliamps into the positive rail...the negative rail will have only 50 miliamps of power consumption.
Observing the discharge without audio into the input for sure the positive led will be off in advance related the negative Led.
But if you switch off having audio into the input...well... this way they will go off at same time as this difference will be not significant face the much more energy will flow both rails.
regards,
Carlos
last movie about the Trust
some seconds playing Pink Floyd.
use good speakers and good amplifier to reproduce.
You have nice treble and deep bass...small PC speakers are not enougth.
Carlos
http://www.youtube.com/watch?v=tCgfcnGJetE
some seconds playing Pink Floyd.
use good speakers and good amplifier to reproduce.
You have nice treble and deep bass...small PC speakers are not enougth.
Carlos
http://www.youtube.com/watch?v=tCgfcnGJetE
Hello!!!
...you're bottomless in you're research of hifi amplifier
...you're never tired!!
I have just 1 question for you, which of following amplifier, DX amplifier, DX HRII amplifier, DHR Turbo, DHR trust or ESP P101 of Rod eliott have the best soustage, the best "aeration" between musician?
...you're bottomless in you're research of hifi amplifier
...you're never tired!!I have just 1 question for you, which of following amplifier, DX amplifier, DX HRII amplifier, DHR Turbo, DHR trust or ESP P101 of Rod eliott have the best soustage, the best "aeration" between musician?
DHR Turbo is the prefered one by my family, test folks and friends
And it is not too much different compared to the Dx Standard.
This one has this "air" you said.... best aired between instruments.
About Rodd Elliot amplifiers i do not know...i do not assemble his amplifiers, and because of that i have not compared.
Rodd Elliot is a very competent guy, he know more than i know...more skilled and someone that helps our communitty teaching and informing interesting things..... i suppose, because of that he may produce nice sounding amplifiers.
I had some trouble with him.... many years ago..and this made me not very confortable even to visit his pages..i am the worst guy in earth to evaluate his products.... i use to ignore his existance..but this is personall and you should not do the same.
C'est la vie... au passè rien du plaisir...toujour c'est très bonne.
Carlos
And it is not too much different compared to the Dx Standard.
This one has this "air" you said.... best aired between instruments.
About Rodd Elliot amplifiers i do not know...i do not assemble his amplifiers, and because of that i have not compared.
Rodd Elliot is a very competent guy, he know more than i know...more skilled and someone that helps our communitty teaching and informing interesting things..... i suppose, because of that he may produce nice sounding amplifiers.
I had some trouble with him.... many years ago..and this made me not very confortable even to visit his pages..i am the worst guy in earth to evaluate his products.... i use to ignore his existance..but this is personall and you should not do the same.
C'est la vie... au passè rien du plaisir...toujour c'est très bonne.
Carlos
- Status
- Not open for further replies.