Analog Paper^2 Discussion and Appreciation Thread. - Page 3

Thanks for the impressions, Ian.

 

The "tinging" noise you describe sounds to me like the tubes settling. It's not uncommon in tube amps to hear this; basically it's due to the microphonics of the tubes and casing.

Thank you so much for that info MF, I really appreciate it. Though I have listened to many tube amps over the years this is the first I have owned so your thoughts are really helpful. Any advice on good housekeeping with tubes?

I read somewhere it is good to clean the contacts with isopropyl alcohol?

I do like the way a tube amp is a more interactive thing than a solid state. It is like a machine has some soul which I love.

Thanks so much again, You are always such a mine of useful and helpful information.

Could this `tinging' be alleviated by fitting tube dampers or will it fade as the tubes settle?

 

Andy.

 

Tube microphonics have never been enough of a bother for me to try dampers, but that could work. In my experience it usually happens more when the amp is first powered up; once the amp have been left on for a while the tubes have warmed up and don't "pop" anymore.

 

Cleaning the pins of tubes is a good idea if they're dirty, only because it improves contact. A dirty tube can produce buzzing or other static noise. Clean tubes will settle just as much however, it's just natural as far as I know.

 

An experiment: try gently tapping one of the tubes with your fingernail (don't contact it with your skin or you may burn yourself). If the sound is remotely similar to what you've been hearing, then it's the microphonics of the tubes. Don't worry, tapping the tubes or bumping the amp chassis wont hurt them. Just don't hurt yourself!

Edited by MuppetFace - 1/20/13 at 3:08am

That is a beautiful amp, Ian! 

 

Really curious about the impedance selector. That could be gold. What are the settings?

cooperpwc,

 

I was curious about this too and emailed the designer. Apparently there are three impedance possibilities -   (Lo (~ 32ohm), Mid (16 ~ 64ohm), Hi(32ohm ~ 200ohm) and two can be specified on the amplifier to correspond with the sliding switch. 

 

Andy.

 

 

Thanks! But darned if I understand it...

 

So if one is using 16 ohm headphones (like Ian's PF IX), would one be better with Lo (as one would expect) or Mid?

Paul and Smial.

This is the great thing about Shikata San. If there is something one needs is accommodates! I told him the headphones I would be using and he set the gain to two settings with that in mind. First is low which is 8~32ohm and the second is mid 16~120

There is also an option of hi which is 64~200 if you need that. I think he set mine as they are so that no matter what setting the PF's would always be safe. I will be taking the amp to my local coffee shop this morning and meeting a friend as he wants to try them out with the K701's I gave him a couple of years ago, will report back later!

Also, about the tinging. It has all gone now! I think it is three fold. One, it has more hours on it. Two I have increased the damping a little in the cradle I have made for it so as to separate it more from its physical environment and three. As the tubes are NOS I thought it would not do any harm to do what MF suggested so I cleaned the pins with pure alcohol and replaced them.

This has no led to absolutely zero noise when playing even the quietest passages of music and the slight swish noise with no music playing and volume turned to max is now not there either. I had no idea tube amps could be so quiet!

For info, he quotes battery life as 7 hours. For info purposes I tested this and he is spot on. It then takes two and a half hours to fully charge again but he recommends not draining the battery completely so on average with a couple of hours still left on the battery your looking at an hour and a half charge time.

 

Ah! The ability properly to drive 8~32 ohms is remarkable for a tube amp. Very cool.  

Couple of things from Shikita sans Facebook page.

First, he has today introduced a portable hybrid tube amp, looks much smaller than mine and the tube section runs two 1U4's
Here is a link to his web page though it looks like the words are not up yet.
http://www.analog2p.com/tur06/tur.html

Secondly, I have no idea what these mean but these are two Oscilloscope readings from the TU-05. His comments on them accompany them.

"Fully synchronous step-down and step-up switching switching, eliminating the noise of the beat.(DDC 3.0)"



"Beautiful impulse response"

I saw the post on facebook, and if price is good, I would really want to get one :D

 

Somehow, the leather bag for TUR06 looks very nice :D

And, I am not sure..but I think he meant noise can be eliminated by doing step up and step down switching??

 

When I look at the first picture, when the signal is stepped up to 45V ish (probe1) from 5V ish(probe2), I see the reduced noise....I think that's what he meant? :0

Edited by juntom10 - 1/21/13 at 11:34am

Yeah, when it comes to technical things I am about as knowledgable as a lump of coal it is a very very quiet amp even with the PF's which are pretty sensitive.

I am now having fun researching about tubes and have ordered a few so far so will have some fun tube rolling soon!

Any idea if these are up for sale?

The bag or amp? I think both are now up for sale but for me the page words do not show up as Japanese writing so I can't translate it Di-Ma is really friendly, I would send him an email and ask.