kaneda preamp

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One of the issues of MJ I have, did a kind of retrospective of Kaneda <a href="http://www2.gateway.ne.jp/~mutsu/e/hp027.htm">(Kaneta)</a> phono stages, next was:
 

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Tvi,

you call this final ? My MJ article collection is starting 1992 and there are a lot of Kaneda preamps ;-)) - sadly, they are ending in 1998 or so, because the subscription stopped for unknown reasons. But my friend who had the subcription, he intends to buy the last volumes soon.

regards,
Hartmut
 
Jam:

Both our cartridges and electronics are currently all made in Japan. When it comes to things like machining, Japan has exceptional quality (among the very best that I have ever seen). OTOH, the more quality I experience, the more I demand :devily:.

Living-wise, Tokyo is a phenomenally convenient, well-equipped city. There are lots of nice restaurants, LP stores, things to do, and places to see. And there is always Akihabara (great place for collecting components to build prototypes and one-off units). OTOH, the costs of doing business in Japan are very high, and so are living expenses.

Japan also has a very active and competitive high-end audio market. Whether your tastes are SET and horns or SS and planars, it is easy to get interesting equipment. And due to this ready availability of top-line equipment, it is also easy to judge where your latest designs stand in relation to North American and European manufacturers like FM Acoustics, Goldmund, Spectral, Rowland, Levinson, Boulder, Classe, Pass, ARC and others, in addition to local brands like Kondo (AudioNote), Bridge Audio Labs, Luxman, Wavac, Marantz...

regards, jonathan carr
 
Source of components for Kaneda Pre?

I am looking for a source of the semi-conductors for the Kaneda Pre #1.

Otherwise, equivalent modern day pieces (which may be better).

Also, how much current at the +-35v or so does it draw? (considering battery power).

Voltage gain and output impedance?

Thanks!!!!!!

p.s. I may build this circuit instead of a tube pre-amp. It is fascinating.
 
Richard: What "Kaneda Pre #1" do you mean, and where have you seen it? Musen to Jikken started running the "Kaneda Project" series of articles from the August 1973 issue, pages 199~207. The inaugural project was a phono stage and line amp combination, and this is the real Preamp #1. Although Kaneda _may_ have penned an isolated article or two prior to this Musen to Jikken issue, I doubt if these are considered as part of his famous Numbered Series.

The Preamp #1 topology is a dual differential with resistive loading throughout, and the output stage is a single NPN follower with a resistor tying the emittor to the minus rail.

The input FETs are 2SK30 (GR rank), second-stage 2SA493 (GR rank), and the output stage 2SC1000 (BL rank). I believe these were all probably by Toshiba, but I don't know for certain.

I believe that the only device currently available today is the 2SK30.

regards, jonathan carr
 
Re: Source of components for Kaneda Pre?

RichJones said:
I am looking for a source of the semi-conductors for the Kaneda Pre #1.

Otherwise, equivalent modern day pieces (which may be better).

Also, how much current at the +-35v or so does it draw? (considering battery power).

Voltage gain and output impedance?

Hi Rich,

I can provide you a set of 2SK30, 2SA872 and 2SC1240 which are an alternate choice for the 1st Kaneda, the 2SK30 are matched but used. I object to using more modern semiconductors, I tried some, but results are worse. Power consumption is about 12 mAmps for each amplifying module: 10mAmp for the output stage, 1.2mAmp for the voltage amplifying stage and 0.5mAmp for the input stage. Open loop gain is said to be 70dB. With the emitter follower output running at 10mAmps the output impedance is always quite low, in the 20..30 Ohms region.

regards,
Hartmut
 
Having no idea of what design L'Audiophile chose to publish and promote as "Kaneda's Preamp #1", I felt that it would be instructive to show the real amplifier schematics for the original Kaneda Preamp #1, pretty much as they were first seen in Musen to Jikken nearly 30 years ago.

The attached file is close to the original drawings in most particulars, but deletes various non-essential features like a channel balance and variable bass-boost.

The accompanying positive and negative voltage regulators are of the series-type, with uPC55A (NEC?) opamps as the error amplifiers. Also note the use of asymmetric power supply rails.

This design almost certainly _cannot_ be built as shown, because
both the 2SA493 and 2SC1000 are long-extinct. It should therefore be regarded as being primarily of historical value, but also reflects a desire on my part to keep the records straight.

regards, jonathan carr
 

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Hey guys,

last week I complete the Kaneda phono stage preamp (as I have already build a tube line preamp). I put it in a shielding case with a seperated power supply.

Well, what can I say is it sounds great and sweat, it's incredible quiet :eek: . The noise and hums are originated mainly by tube preamp. Actually it's is still in warm up condition. I'm very satisfied about this!:D

I choosed 2sk30 as input, and the second stage I used 2sa970 (a well-known low-noise transistor), and for the output I replaced the obsolete one with 2sc3112. All transistors are matched with a tollerance of +- 1 hfe and shielded too.

The biasing and off-setting is a little bit complicated. Because there is no resistor at the output emittor so the bias and the off-set is somehow dependent one to the other. It takes quite long for adjustment, need much patient!

The next step for me is to upgrade the power supply: I should put a choke and more capacitors!! hehe:devilr: .

Cheers

Mincy
 
Adjusting the Kaneda Phono

Hello Mincy,

there are some tricks to do the adjustments:

first adjust the second stage or VAS (voltage amplifier stage) current so that the mathematical sum of voltages at the two output resistors of this stage is 1.2 Volts.

then adjust the first stage so that output offset before the output capacitor is about zero.

the trick is that the sum of voltages at the collector resistors of the second stage is (nearly) independant of the bias voltages. As you need 0.6 Volts to drive the output transistor for zero output DC bias, you need a total of 1.2 Volts, e.g. -3 Volts and +4.2 Volts would do the thing.

Don't mind a small asymmetry of 1 Volts or small bias lower than 1 Volt. The DC bias is very delicate: when you blow gently at the transistors, you will likely see a change in offset. There are no detectable sonic differences between perfect bias and symmetry and small imperfections.

best regards,
Hartmut from Munich
 
HI
I would like to ask for help or some idea about the Caneda preamp.
I desiseded to give a try these famous preamp , so I made the pc boards and I purchase the parts what I could find or was avaleble in the stores were I used to purchase the parts .
For jet I purchase 2SK30A Y type unfortunatly I dont find the GR type .
Transistors 2SA872AE , I think these OK , and for the remaining transistor I purchased 2SC1312C ,unfortunatly only C type was avaleble no A type .
I want to build after the schematic from the Bonavolta website .
I would like to ask for help if I can use these parts , do I need to change some resistor value ect. I know there is a diferentsce beetwen the GR & Y type jet .
Thanks for any help and any comments .
Regards
 
Hi Jeno,

nice choose!! try kaneda pre you won't regret it!! but don't stop here, do other pres to try different TASTE;) .

Those jfets and transistors fit well, the differences are unnoticeable, unless you use different components. Remember, as it is the most important, to match them: Id for jfet, HFE for transistor. Besides, earthing and shielding are very important, as phono signal is susceptible to disturb, so pay more attention.

After finished let us know your impression!!

Cheers

Mincy
 
HI
Today I finnised the Kaneda preamp . Unfortunatly I have some ofset problem .On the output I have 1.8V dc volt .Then I adjusted to the minimum with the trimpot . I can increase up to 1.8V but decrease only 1.3-1.4v posible .
After these problem I tried to change the mosfets the 2SK30 to 2SK170 at one side .
Now on that side I get 0.9V on the output .
I would like to ask for help , I dont know how I bring done that ofsett close to 0V .
I was afraid to conect some sourse to test it if it works or not .
I tought to replace the 27K resistors but I'm not sure if that would resolve these problem.
I use 2x25V AC transformer , after the bridge I got around 37VDC .
Please if someone can help me , or have some idea please let me know .
Regards
 
HI
Yestarday I manege to adjust the ofset close to 0V . After I replace the 100R trimpot with 470R.
I did the first listning test , the sound is warm , detaild I think is better than my SOZ . But I belive there is room for more improovment .
I would like to ask for some help , I dont know how to matche the SK30 JETs .That was the reason for the high ofset .
The transistors are fine , I matche the hFE close to 1%.
I would like to ask for help about how I can matche the jets or if some one know from were I can purchase matched pairs that wouldbe great to .
Any help or idea is welcolme .
Thanks
Regards
 
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