Need help with sound distortion

[Wally]

Hi, I have a problem I hope someone can fix. I have a Thorens TD850 Turntable which I have always used as a separate entity using Bose amplified speakers with which it has always worked well. I decided to incorporate the turntable into my normal System and a problem became apparent. That is that no matter what I tried or how I connected the turntable it was coming thru distorted. I use a Pro-ject phono preamp with the Bose speakers. Connecting the turntable to a Yamaha RX-A1020 receiver Thru the phono input with and without the preamp I get distorted sound. I also have an ONKYO TX-RS875 receiver which I also tried with exactly the same results. I then tried connecting thru nomad inputs again with the distortion. Going back to amplified speakers it works well. Leaving the system as is is not what I want as the Bose speakers are 90 degrees to my seating position which is not conducive to good stereo listening. The project preamp definitely works as I can just here the music thru the Bose speakers without the preamp, connecting the preamp gives me normal volume levels. Anybody with any idea as what could be causing the distortion would be of great help as my expertise (as it is) is done and dusted.
Thank you. Wally

[The Grand Wazoo]

I think you may be running your signal through two phono stages - try plugging the Project pre into another (non-phono) input - Aux or tuner or something similar.

[Wally]

Thanks for the reply, I have tried thru ordinary line inputs with and without preamp. I really don't think there is anything I haven't tried. I'm wondering if it's the output or lack of from the preamp into the receivers. As I said it works fine with the amped speakers.

[Macca]

I've used a Project phono amp with a lot of different amps and never had this issue. What cartridge are you using? Does the Project have the dip switches on the bottom? If so try adjusting them to different settings - there is a guide in the manual IIRC

[Wally]

Unfortunately, I have seriously attempted every avenue to fix this problem that is physically possible without test equipment. The stylus I'm using is an audio-technica AT440MLa. As I've said, it works perfectly with the amplified speakers. The Hi Fi outlet that I purchased most of my gear from are going to test the preamp for me to see if it has a problem. Unfortunately I'm a long way from the outlet & will have to wait until I can get up there. In the meantime I was hoping for any other ideas that I may have missed.
Wally

[73Chaz]

Hi

Can you give us some details on what the distortion is like? Crackle? Clipping?

I'm wondering if the second system is revealing something that the Bose speakers do not.

Regards

chaz

[synsei]

Which model of Pro-Ject pre-amp is it Wally?

The chances are this issue is something silly. I doubt there is a problem with the Pro-Ject otherwise you would be hearing distortion on whatever it was connected to and as you have already stated, it works perfectly fine hooked up to the Bose'. Check that the cables are in a sound condition and that you are hooking them up to each unit properly. I'm sorry if this sounds bloody obvious but hooking stuff up wrong can happen to the best of us. Now, I note that both the receivers that you mention are home cinema amps, do you have an old two channel stereo amp lying around the place? Even if it is a crappy old garage sale find it will serve its purpose. If so run the Thorens and Pro-Ject into one of the flat inputs on the stereo amp, Aux will do nicely. Report back with the results once you have done this. If you don't have a stereo amp, can you borrow one from somewhere?

[walpurgis]

If you can, borrow another phono stage and see how that sounds. Yours may have a problem.

Have you checked your cables, maybe there's a problem with the interconnect (shorting/bad soldered joint).

Do you know anybody with a turntable you could borrow and try on your system to see if the problem is present with another TT ?

What tracking force are you using? I'd be inclined to use the upper end of what is recommended (1.4g to 1.8g). Maybe even using 2g to achieve secure tracking.

Is the tonearm moving freely, No binding of bearings or wiring pulling? Although if your TT works OK elsewhere it's probably not that.

[synsei]

I doubt the problem is with the phonostage Geoff or it would misbehave into the active Bose' too. The two receivers Wally mentions are both AV amps so I suspect the problem is a set up issue, which is why I suggested he try a regular stereo amp. I refer you to my previous post ;)

[walpurgis]

I doubt the problem is with the phonostage Geoff or it would misbehave into the active Bose' too.

I was thinking of input mismatching Dave. Another phono stage may work more sympathetically with Wally's main system.

[synsei]

I was thinking of input mismatching Dave. Another phono stage may work more sympathetically with Wally's main system.

Of course, sorry, I've not slept yet does it show? :doh:

[Wally]

Hi, yes I have checked cables & everything you guys are suggesting, I am using my gear thru an Emotiva EPA-2 AMP out of the pre outs on the receivers. Have tried thru the receivers only as well and still get the distortion which is a low to high garbled sound, understandable voice but distorted.

[synsei]

Have you tried running the Thorens/Pro-Ject into a standard two channel amp Wally, and which Pro-Ject stage is it?

[Wally]

The mis match sounds to me a possible solution. I have arranged to take the pre amp to the Audio outlet who will check it for me. The whole problems will be on the back burner for awhile as I just dropped the control unit for the Thorens turntable. Given that I'm in an isolated area it will take a bit of time to arrange for it to be repaired. The fall destroyed the On/Off switch & I cannot see any possible workaround. Thank You all for your ideas and input to my problem. Will inform you of any positive developments in this saga. The Pro-ject preamp is a Phono Box II. Wally.

[Stratmangler]

There's a button on the back of the Project with MM/MC printed next to it.
Is the button in or out?

There's a fault finding section in the manual http://www.project-audio.com/inhalt/en/manual/manual_phonobox.pdf

[Wally]

Yes I tried the button as well. it works ok. I'm using a MM Cartridge, the button is definitely working as it work well with the amped Bose speakers.

[walpurgis]

Shame about the control box Wally. :(

[Wally]

My own fault for being in a hurry. Checked the price of a new unit and made the heart race a bit. Could buy a reasonable new turntable for what they want for the control box. Hope it can be repaired, even if with a non OEM switch.

[Wally]

Get my control box back tomorrow. will start trying out everything again to sort out this distortion problem. will advise progress if any.