make your own g88

[SteveTheShadow]

One more thing I’d like to do with the Phono1 is a mono/stereo facility, but how to do that is something I’ll have to find out.

Piece of p*ss to do. Just need to find a suitable switch; preferably a mini toggle, same as the Doc used for the on/off switch.
Right and left cartridge negs are commoned at the input sockets, so it’s just a case of using a switch to bridge/un-bridge the two L/R hot pins behind the signal input sockets of the Phono1- job done and nothing in the signal path when playing modern stereo records.

I have a lot of old mono 60s soul LPs that would certainly benefit from the reduction in noise a mono switch would provide.

[Vinyl-ant]

I've got loads of those, had to buy a batch to get the one for your deck

[SteveTheShadow]

Well the mono switch has been fitted and the results on mono records are excellent. A big drop in distortion due to wear on my old 50s and 60s stuff. I found four 1950s British issue, mono Frank Sinatra records in a shop in Malton a few years ago for a quid each. When I got them home I found that though they had been well looked after, they had been played with a ten ton pickup, so there was unfortunately quite a bit of distortion on Frank’s voice. With the phono stage set to mono, I played a few random snatches off those LPs and Frank was much cleaner.

I also tried mono-ing the first two 2009 remastered, stereo Beatles albums, which are basically music in the left channel and singing in the right. These were far better in mono. Although they are not the proper mono mixes, they sound far more natural with the channels summed.

So the mono switch has come in very handy. Perhaps Paul and Tomasz could offer a mono switch as a custom option, for those who want that facility on their phonos.

[savvypaul]

So the mono switch has come in very handy. Perhaps Paul and Tomasz could offer a mono switch as a custom option, for those who want that facility on their phonos.

I remember Nick (Lurcher) saying that he always refused to add a mono switch to amps that he made, due to the possibility of added distortion, but I can't remember any more than that. It will be in the archive, somewhere.

[SteveTheShadow]

Can’t see why a mono switch would add distortion as it is not in the signal path when playing a stereo record, but I’m not an expert.

Best description of what the mono switch does for my old mono records would be the pic below:

EC60F37B-79C2-49BB-B883-A7003B659A89.jpeg (215.05 KiB) Viewed 6409 times

[savvypaul]

Possibly, this: viewtopic.php?f=6&t=44759&p=163576&hili ... ch#p163576

[SteveTheShadow]

Possibly, this: viewtopic.php?f=6&t=44759&p=163576&hili ... ch#p163576

Can’t see the link, apparently I’m not authorised to read that forum.

[savvypaul]

Possibly, this: viewtopic.php?f=6&t=44759&p=163576&hili ... ch#p163576

Can’t see the link, apparently I’m not authorised to view that forum.

Strange...

Here's the text:

All a Stereo/Mono switch does is to short the inputs of the Left and Right channels together, hardly rocket science.

TBH, I have3 to disagree, you are right in that’s often what such a switch does, but I have always refused to add such a switch as its much more problematic than it sounds. If you just short them together, then if you have a signal on the left but not the right, the right output is fighting the left output, increasing distortion on one or both of the signals. You can add a resistive network, but that then costs you gain which you have to make back up, so adding another stage.

The only way I have seen this done without those problems is a complex transformer based stereo mono converter, but then that adds extra transformers in the way as well.

[SteveTheShadow]

Possibly, this: viewtopic.php?f=6&t=44759&p=163576&hili ... ch#p163576

Can’t see the link, apparently I’m not authorised to view that forum.

Strange...

Here's the text:

All a Stereo/Mono switch does is to short the inputs of the Left and Right channels together, hardly rocket science.

TBH, I have3 to disagree, you are right in that’s often what such a switch does, but I have always refused to add such a switch as its much more problematic than it sounds. If you just short them together, then if you have a signal on the left but not the right, the right output is fighting the left output, increasing distortion on one or both of the signals. You can add a resistive network, but that then costs you gain which you have to make back up, so adding another stage.

The only way I have seen this done without those problems is a complex transformer based stereo mono converter, but then that adds extra transformers in the way as well.

I still can’t see why a mono switch is a problem. Theory desn’t match what I’m hearing. I played a 1968 Hollies Greatest Hits original Parlophone mono release just now and the improvement in the presentation with the mono switch was substantial. It was more solid, treble was smoother and noise and distortion from wear was way, way down on the same track played with the phono stage in stereo mode. I’m only reporting what I’m hearing and not trying to be a pain in the arse. People are of course entitled to their views, but on the evidence of my own ears I have to disagree.

Anyway, as you were.

[savvypaul]

I’m only reporting what I’m hearing and not trying to be a pain in the arse.