SUTs are better than "MC head amps" for LOMC cartridges.
I'll defend that one.
SUTs are better than "MC head amps" for LOMC cartridges.
Please do. I'd really like something useful to understand what difference the options make, I've often been tempted to try one but never have.I'll defend that one.
Please do. I'd really like something useful to understand what difference the options make, I've often been tempted to try one but never have.
But for those of us not building our own phono stage and making the other changes, then what's the answer? Sounds like a don't bother, if all that is required to make it work better.Take a look at my article "His Master's Noise" over at diyAudio.com for a discussion. The basic points are that the stepup carries essentially no noise penalty and the CMR allows a balanced input that is remarkably effective at suppressing hum pickup. I can actually touch any of the pins of my MC cartridge with the volume up and not get ear-shattering noise.
Downside is that in order to do things right (and most people don't), you have to tune an RC network across the secondary.
But for those of us not building our own phono stage and making the other changes, then what's the answer?
My phono stage is already, it's the bit before that I'm interested in.Digital.
Thanks.Since you're in the UK, I'd go to Sowter, tell them what cartridge you're using (DCR is important) and what preamp you're using, and get a recommendation for a transformer and network values.
The changes on the PCB looks very much like the standard beginner's modded board. If you need to decouple that much all over your PCB, you've designed it wrong. And why do the star grounding with wires? Shouldn't that be done on the PCB when designed? Maybe go to a four-layer board instead? Or does the four-layer board smear the sound and make it less airy? After the SMD comment, I expect any crazy reply.Hmmm. Is this what a production unit looks like?
The changes on the PCB looks very much like the standard beginner's modded board. If you need to decouple that much all over your PCB, you've designed it wrong. And why do the star grounding with wires? Shouldn't that be done on the PCB when designed? Maybe go to a four-layer board instead? Or does the four-layer board smear the sound and make it less airy? After the SMD comment, I expect any crazy reply.
Just a guess - I wonder if too many boards were ordered at the outset and then design changes were made along the way. Rather than throw out the old boards they just use them this way.
Send it off to SIY so he can test it. Then have SIY send it to me. I will see if there are any repairs needed taking into account the data posted here and from anything SIY reports to me. Once that is all taken care of I will, with your permission, make it into a Gold unit sans the volume control and headphone jack. Then I will send it off to whoever you direct me to. Hopefully sooner than later, after it leaves my hands, someone will actually listen to it.My suggestion would be for Amir to first send to SIY, so he can run his characterization on the same unit. Then, SIY could send to Lounge for evaluation/confirmation. If Lounge then also decides to tweak the unit, I ask that there be an audit trail of all changes/adjustments made, then the unit can make its rounds with Amir and SIY again.
I love this forum for its rigor - this debate is no exception! Thank you, all.
It is a customer's unit sent in to be upgraded. This unit was not finished in the picture you had. It was operational to pass audio and do cursory testing like FR, noise... The finer points of voicing relating to power supply response were still to be done. After it was all done it looked like this,Hmmm. Is this what a production unit looks like?
View attachment 24802
And what is the signal generator? You only show a scope, the meter and frequency counter.
I'm suggesting that dinglehoser sends it to you first.I'm sure Robert will want it directly, but if possible, I'd like to have a crack at it first to verify Amir's measurements and add a few of my own, then I'll send it on to him.
If that's OK with you, please send me a PM.
I'm suggesting that dinglehoser sends it to you first.
No. I got him over a "shock of the new" experience he had. Many of my customers have had similar revelations. The vast majority of vinyl listeners have only heard playback through a standardized set of components. Most phonostage circuits go something like this: low noise opamp(s) with a 20v/us or less slew rate, low cost film resistors or common chip resistors, low cost electrolytic caps in the power supply and often times in other places, power supply rectifier diodes with marginal current rating and slow reverse recovery and the dreaded IMO three terminal preset voltage regulator.... All these things add up to a bloated compressed sound. It's hard to identify until you get to listen to your favorite music without it. Once you do it is like a breath of fresh air but like I said it can be shocking at first.Seems like you bamboozled him with technical jargon.