TeddyPre

[teddy_pardo]

Reducing the gain is very simple, and is less an issue than not having enough gain. I guess that is the reason why manufacturers prefer being on the safe side to be able to work with inefficient speakers and low gain phono stages. I find it strange though that even with inefficient speakers you still have too much gain with several amplifiers.

There is one more point to consider, i have once checked distortions of several amplifiers and found that in some cases distortion level depended on the potentiometer position, where the lowest distortion levels were around 8-9 O'clock and the highest were above 1 O'clock. At full volume distortion went down again to minimum.

 

[mocenigo]

mocenigo,

You're obviously handy with a soldering iron, so you can lower the gain on your 321 boards yourself by replacing one resistor on each board. There are threads around that show you how to do it. This will lower the noise you mention, too.

Not too handy but I could do this, sure. But there are many factors at play

One is that I also want a different sound, for instance, more refined, favouring depth of stage and neutrality to PRaT. The 32.5 (w 729 an 321/5) / 140 combo is sweet, but not elegant (IMNSHO)

Also, everywhere I lived recently has bad or very noisy power (currently, very noisy) and having a better power supply could work. Just putting the ears at a moderate distance from the speakers I head all sounds of noises. Also with other equipment I have at home, completely different chains. This is life in a residential area of Munich today. So either expensive power line conditioners or better power supplies. So indeed I thought, initially, to just replace the HiCap with a TeddyCAP and replace the 321 boards with yours or Avondale's. This still left open the matter of what to do with the power amp.

I want a remote, at least for volume. Of course there are even boards with remote control and so on... I know your wares!

Another factor is that I am leaning towards simplifying the linking of the whole system. The digital side (upstream of the DAC) is going to get more complex in the future. I prefer to keep things lean, and the NAIM approach does not help. I am looking for something that will accompany me for, say, the next 10-15 years.

Another option, and not to turn this into a sales pitch, but Ryan Sound Lab Z250V output boards (replace 321) have 3 gain positions available just by moving a little jumper on the board. Each position reduces gain from the full Naim original (x13) by -10db and -20db (x4 and x1.3 respectively). This reduces output noise from the pot and amp as well as gain. Each -10db is equivalent to having to turn the volume control up 1/4 turn, e.g. brings a 9 o'clock position up to 12 o'clock, etc. With my low output MC cartridge and low efficiency speakers, I need the full gain but many others use lower settings for better resolution on their volume control.

Thank you very much, I do not consider this to be a "sales pitch", at least not a shameless one, I read very favourable opinions of your boards. As far as I know and read, you are pitching good stuff at good prices.

They were definitely an option, but changing power amp, pre power supply, and buying your board set (Custom Set w/Remote Volume Control) would be cheaper, than just changing everything, but not dramatically so.

Roberto

 

[mocenigo]

There is one more point to consider, i have once checked distortions of several amplifiers and found that in some cases distortion level depended on the potentiometer position, where the lowest distortion levels were around 8-9 O'clock and the highest were above 1 O'clock. At full volume distortion went down again to minimum.

This sounds weird at first, but only to non-technical people. In industrial design one often tunes parameters at only a few data points. Like AF calibration for zoom lenses only at the tele and wide ends - I see this when I watch attempts to minimise power consumption on complex systems on chips.

Assuming that most physical objects have a linear behaviour, this would work to minimise aberrations of measurable physical parameters across the board. As you definitely know much better than me, many things are not as linear as we would like with electronic circuits...

Roberto

 

[YNWOAN]

The main issue with electrolytic capacitors is that when they get older their internal resistance (ESR) increases, so they become less effective, like an old battery.

We use electrolytic capacitors but we don't rely on them to do the filtering job, we can therefor use smaller capacitors with higher ESR, and even when they get old and their ESR increases it has no effect on the power supply performance (we have compared low and high ESR capacitors, there was no difference). The filtering job is done by long life Tantalum capacitors and film capacitors, and even there we use 100K resistors in the filter, so even if the ESR increases up to 0.1 Ohm it is totally negligible.

Thank you for that, very well explained .

 

[mocenigo]

The main issue with electrolytic capacitors is that when they get older their internal resistance (ESR) increases, so they become less effective, like an old battery.

Is that age or actual use (i.e. they get old when they are used)?

I am asking because there is a huge difference in my equipment between when I use the HiCap and when not, but my HiCap is not very new (I got it from Jun Keller in 2006 IIRC and it was apparently serviced in 2002). The equipment has been used very little in the last years because of my frequent travel trips (sometimes I haven't powered up anything for months).

Roberto

 

[teddy_pardo]

AFAIK age rather than use. I think that unless being used at extremely high temperature, it's better to use them than not to use them.

 

[RyanSoundLab]

Well you are certainly looking at a very extensive overhaul of your system! So many options! You mains source noises sound particularly troublesome. Many of us have installed direct wiring from the service entrance to the hifi system to help reduce those effects while also improving its sound quality. This may not be an option if you are in a rented apartment, of course. Best of luck in getting your system where you want it to be.

 

[mocenigo]

You mains source noises sound particularly troublesome. Many of us have installed direct wiring from the service entrance to the hifi system to help reduce those effects while also improving its sound quality. This may not be an option if you are in a rented apartment, of course. Best of luck in getting your system where you want it to be.

Sadly I cannot do that. I am in a rented apartment. I may resort at some point to set up some kind of power line conditioner...

Roberot