Aikidio Phono Amp Questions

[JustinJ]

Hello All,

This will be my first audio project and I am leaning towards the Aikidio 8 tube phono amp. I have been studying electronics for a little while and did a few small kits to learn how to solder different components. I am still working on getting a knowledge of electronics but want to attempt a phono pre amp.

My current equipment is Martin Logan Source speakers and a Harman Kardon 3490 Receiver. I am running a Techinics 1600 SL with a Denon DL-160 cartridge. I am thinking that the tube sound will be a nice balance with the electrostat speakers.

Here is the amp that I want to build:

Aikido Phono Preamp Kit


I am new to tubes but know that I need to use 12volt tubes. I am going to need about 50db gain due to my cartridge being at 1.6v although I have heard the Denon cartridge runs at 2.2v.

Tubes:

What tubes should I use if I am looking for quietness and good sound stage? I want to purchase the tubes from the same place.

Resistors and Capacitors:

He offers carbon or metal resistors. I have not done electronics long enough to know what is the best choice. I notice that the carbon resistors have a 1% tolerance but with a lower watt capacity. The metal resistors are 5% tolerance but with a higher watt capacity.

What type of resistor should I use and why?


Capacitors:

RTI Capcitors or Oil in paper capacitors? I am not even sure about the benefits either one of these.


Power Supply:

I am still trying to understand circuits right now and have yet to delve into power supplies.

I see two kits that he sells


This one

PS-1 High & Low Voltage Regulator Kit


This one:

Janus Shunt Regulator Kit


Which one of these power supplies is going to give the best sound? The price difference is not too drastic and they look like they both only need a transformer to complete them.



I really want to do this right the first time but still not overspend by too much. I appreciate any help that anyone could give me.

I am also open to other phono amp projects but do need to stay within the same budget.


Justin

[DougL]

Here is the Owners manual for this Kit. http://www.tubecad.com/2008/07/13/PH...o%20preamp.pdf

I am new to tubes but know that I need to use 12volt tubes. I am going to need about 50db gain due to my cartridge being at 1.6v although I have heard the Denon cartridge runs at 2.2v.

I assume you are looking at 12AX7, which according to the manual will give you a 46 db phono pre from this kit.

What tubes should I use if I am looking for quietness and good sound stage? I want to purchase the tubes from the same place.

I would start with current production tubes sources from a reputable vendor. To me, most of the magic is in the design, so asking about sound stage of the tubes makes my head hurt.

What type of resistor should I use and why?

Either type will work. Metal Films are quiet and stable. My understanding is that carbon films give a slightly more "vintage" sound. YMMV. Go with the metal films unless you have a strong opinion

RTI Capcitors or Oil in paper capacitors? I am not even sure about the benefits either one of these.

RTI are good film caps. If you want to research film caps for the next 6 months, have at it.

Which one of these power supplies is going to give the best sound? The price difference is not too drastic and they look like they both only need a transformer to complete them.

Either will be very good. If it were me, I would build the unregulated supply in the manual and upgrade later. However, well thought out regulated supplies are usually "better".

HTH

Doug

[Bas Horneman]

He offers carbon or metal resistors. I have not done electronics long enough to know what is the best choice. I notice that the carbon resistors have a 1% tolerance but with a lower watt capacity. The metal resistors are 5% tolerance but with a higher watt capacity.

Actually. He says: All the resistors (either 5% 1W carbon-film or 1% 0.5W metal-film)
So the metal-film have higher tolerance with lower watt capacity. The watt capacity is not important in this setup. The tolerance is important.

I prefer carbon-film buy many prefer metal film. It is pointless trying to ask someone else what is best. I don't think it makes all that much of a difference. But it is important that the resistors are almost exactly the right value. So check them. They might have a 5% tolerance but they could be all spot-on.

[JustinJ]

Thank you for the help on the resistors and caps. I really did not know if it made a difference. I do not want to research the caps for 6 months and question the value of some of the really expensive caps.

Bas,

Thanks for catching my mistake. I was going off the top of my head. It sounds like a good thing is the carbon resistors.

I was looking at the 12AX7 tubes.


Have either of you built the Aikidio phono preamp? It seems for the money to be a good value as far as a kit. I looked at the bottlehead amp but the Aikidio looks to have a better design and cost less. I am new to this and still trying to learn.

[DougL]

question the value of some of the really expensive caps

You are sane. , good. Caps do have different dielectric losses. Its just that after a certain point, its very subjective.

Have either of you built the Aikido phono preamp?

I have not. I do have a 9 pin Aikido line stage.

Good luck with your build.

Doug

[mllum]

I have built the 2 Aikido phono preamps from the very first batch of pcb's. One for myself and the other for a friend. I am using Allen Wright's Super shunt regulator in the power supply . All I can say is that the Aikido phonopreamp is fabulous sounding with a deep and widesoundstage. Mind you, I was using an audioresearch, PH-1 and PH-3 prior to this and yet these are now gathering dust.

Incidentally, I run a Linn Sondek LP12 with an Alphason tonearm and an Audio Technica ATOC9 mc with an Audio Technica step up transformer and like you, my speakers are very revealing in that they are Quas ESL63's.

TheAikido Phono is highly recommended.

Just my 2 cents worth.

[johnsonad]

Have you built the Tetra stage? I have one in the box awaiting a build. The manual is confusing as hell.... Should get around to it this summer after an amp build.