Phono3 new build hum

[Steebo123]

I agree to a point but having used lower price coils, (denon's, AT's) over the years, I feel a good MM beats a lower cost coil. Never been able to afford (yet!) a £500 plus coil, but who knows in the future. I have heard the 1042, and its Audionote variants, sound great in demos, and I am sure it will do for now.

[Richard]

Originally Posted by Steebo123

I agree to a point but having used lower price coils, (denon's, AT's) over the years, I feel a good MM beats a lower cost coil. Never been able to afford (yet!) a £500 plus coil, but who knows in the future. I have heard the 1042, and its Audionote variants, sound great in demos, and I am sure it will do for now.

I've heard people say that but have never found it to be true except maybe against the 103. The 1042 is way over-rated imho. The humble ATF5 and DL110/160 are better and not affected by load and capacitance and so give a more consistent performance.

It may be that sometimes a 1042 suits a system but the MCs are more open and natural sounding. I wonder if Phono 3 is now letting you hear the 1042 for what it is?

Do try the 5751 valves and set the trimmer caps to midway then compare the overall balance in the system against a decent CDp. The CD may not have the same space and realism but will give you an idea if the cart is too toppy which may be causing the spit.

Capacitance, load, tracking may be the reason and the Rega arm is awful for adjustment. On one sample I had the tube was twisted so the cart and bearings weren't aligned.

[Steebo123]

Hi everyone, I have fitted OsCon bypass caps now, plus replaced the metal film R1/R2 with carbon types. Much better sound, more weight and openness. However, if I turn the volume up more than half way (no record), I can here noise, especially from the left channel, and a little bit of radio breakthrough. Is this just down to the increased gain? I will try 5751's (do I need to use three?), just waiting for pay day to use the GE ones. Ironically I work for GE......

Thanks.

[Richard]

Hi Steve,

That's good news then so far. The 5751s will drop gain to the previous level of ecc83 without cathode bypass caps and you can use just 2 and leave an ecc83 as output if you wish and get another later if you like the sound.

Re the noise we don't know what level more than halfway is relative to your usual listening levels so don't really know how much of a problem the noise is.

The way to check the cause of it is to short the inputs of phono by inserting phono plugs or a phono lead with the centre signal pins connected to the outer earth shells. This eliminates the deck/arm/cart as input and will show if they are the source of the noise. If it is not quiet then (bar a bit of thermal hiss) the cause will be in phono or further down the line.

If it is then quiet and is showing the deck wiring as problem look first to the Rega arm as they are (or used to be at least) earthed via one channel earth braid. Has yours been rewired and does it have a separate earth wire?

[John Caswell]

One of the first things to do when you find noise is obtrusive is to juggle the valves around with the noisiest finishing up in the Cathode follower o/p stage.
The big problem of course is finding "quiet" valves.
For instance I have just sorted a PSU/Pre/Phono III combo which was supplied with TJ valves. Don't know whether the guy was unlucky but they were atrocious, noisy as hell. As an indication, with v/c at 11o/c noise was very apparent on quietish music but with my reference Mullard ECC83s the v/c could be turned to 3 o/c.
I would certainly fit metal film/metal oxide Rs to the first grids, both the anodes and cathodes and to the final c/f cathode as these are all in the signal path. I have fitted bulk foil resistors in the grids and anodes of my Phono III and they are quiet but at £14.00 - £20.00 ea they should be.
The quietest metal oxide Rs I found were the old RS components 1/2 watt types but sadly no longer available.
Hope this throws some light on noise.
Of course you could always run it at Absolute Zero but then the refrigeration noise take over

John

[Steebo123]

Hi Folks, got some 5751 (Philips type), and popped them in. Good news is the noise is unobtrusive now, and with no record playing, can only be heard with volume at about 3 o'clock, way louder than I would play an actual record. I assume due to lower gain.

Bad news is the sound so far seems harder and more "hifi" but less natural.

Will give it a few days of course.

Cheers

[bob orbell]

Hi Steve, you say your new valves are Philips type? if they are Philips Jan, military valves they should be very smooth. I still think it is your cartridge arm combo. that Colin has stated, that is your problem, have you tried adding a few pF in the phono to see if that helps, may be start with 500pF, that should be very diffrent, then come down from there, ortofon used to make a capacitor that fitted on the cartridge body, they may still do, I think it was about 190-220pF, it is to tame the HF rise of MM cartridges.

[colin.hepburn]

Originally Posted by bob orbell

Hi Steve, you say your new valves are Philips type? if they are Philips Jan, military valves they should be very smooth. I still think it is your cartridge arm combo. that Colin has stated, that is your problem, have you tried adding a few pF in the phono to see if that helps, may be start with 500pF, that should be very diffrent, then come down from there, ortofon used to make a capacitor that fitted on the cartridge body, they may still do, I think it was about 190-220pF, it is to tame the HF rise of MM cartridges.

AS bob has suggested have a read of this review as it may help you with the 1042 cart VTA (Vertical Tracking Angle) adjustments and resistive and capacitance load
http://www.tnt-audio.com/sorgenti/g1042e.html

[Steebo123]

Yes, they are the Philips Jan type. The cartridge was dealer set to adjust VTA etc, so I am sure this is fine.

Will persevere!

[pre65]

Don't assume dealers always get things right.