• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

need help on treble distortion with my EAR834p phono

bigpandahk

Member
2009-07-22 3:28 pm
I am a new diyer and built a EAR834p couple months ago. It sounds great but has distortion (like overload) on high frequency loud vocal playback. I've tried replacing tubes, added volume control at input to lower the input level but didn't help. Can anyone advise what is the possible problem or method to trace the problem?

Many thanks for your help.
 

artosalo

Member
2010-02-16 9:00 am
Also check if the RIAA is correct, this is best done by applying a signal from a signal generator through an inverse RIAA circuit to the input.

I think inverse RIAA corrector is quite rare in typical diyer's lab.
You can do the check of the frequency response of your amplifier simply by reading the relative voltage levels and comparing these with the RIAA table given below:

RIAA Curve
 

bigpandahk

Member
2009-07-22 3:28 pm
built the inverse RIAA and checked everything work fine. I also connect the CD player to the 834p through the inverse RIAA, no distortion.

So the problem should be related to cartridge or tonearm.

I've removed the tonearm from the TT, re-install it with all alignment being done from the very beginning. No improvement. I am using SME V + dynavector 17D3 + VPI TT. I also tried my old cartridge Blue point special, still have distortion but not as worse as 17D3.

Can anyone help me????