kaneda preamp

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jcarr said:
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.

T

The "original" diagram from L'Audiophile is linked by arthur in post #3 in this thread...
http://www.bonavolta.ch/hobby/en/audio/kaneda_p.htm

This is the one I built, but could not balance the line stage built with discretes instead of monolith Qs. I have been thinking of using the 2SK30 also in the line stage, as I still have a few extra... don't know if it's worth the effort ,though....???
 
> is it worth reading?

Well, if you already know his full-symmetry circuit, then you might find it boring, except perhaps for his component choices, etc. This is because he uses the same basic circuit topology for everything -- buffers, preamps, phono, power amp, ....

For example, I find it interesting that he uses 2SK2554 for his power amps. So for me it is still interesting.

There are lots of tube circuits as well, but I am not into tubes.

A friend got them (2 Volumes) for me in Japan for approx. 26 Euros each. At that price, I don't have to think twice.

There are also a few variations of protection circuits. His PSU's are all NOT regulated, just caps after rectifiers !!!!

For beginners, it is a great book. Very detailed instructions, lots of drawings & photos, very tidy layouts (all point to point on universal boards, no etching). Theories very well explained.

>does it contain more than the last years MJ magazine articles?

I don't know the magazine, so can't answer that one.

> Am I correct that this book is only available in japanese?

Yes. But I am sure you, like me, can read circuit diagrams, mechanical drawings, transistor curves..... What more do you need ?

I think it is worth the money, if only as a collectors item. But that is of course only my personal opinion.

PS The circuit in the book is somewhat different to that shown in the link :

http://www.bonavolta.ch/hobby/en/audio/kaneda_p.htm

though they commonly have diff pair first & second stages, followed by N-Type transistor quasi-pushpull output stage. Very similar to the Yamaha Power JFET amps in the 70's. (See Nelson Pass Zen V8.)


Patrick
 
Kaneda preamplifier

I built the Kaneda preamplifier in 1988 with the recommended
components including 2SK30AGR/2SA640/2SC984. After a few
listens I noticed the sound had a very slight amount of
distortion. I compared it with another preamplifier I had heard
before which sounded remarkably open and distortion-free.
I figured a while what to do about it and came to the conclusion
that if the feeding voltages, in this circuit + - 35 volts, is a bit too
high, light saturation of some transistors occurs and the output
signal is affected. With some experimenting I lowered the feeding voltages to + - 24 volts (+ - 20 volts via a trimming resistor to the line stage) did the trimming points without major problems just ever so slight instability which seems to be unavoidable, and, my beliefs were right, the sound from the Kaneda preamplifier became improved, open and natural. A minor loss in dynamics should be a drawback but with an over-dimensioned power supply capable of delivering current it is not significant. Also a few modifications in the RIAA-correction is of importance to achieve a more linear curve. This was published in the Swedish music technical magazine Musik- och Ljudteknik (1-1992). Replace decoupling capacitors 1.5 nF>1.33 nF (1 nF + 330 pF),
4.7 nF>4.72 nF (3.9 nF + 820 pF), decoupling resistor 51K>56K and T2 gate resistor to ground 1.2K>470.
/I. Söderholm
:)
 
Here's the schematic and layout of a folded Kaneda-style discrete opamp, with currently-available SMD parts. The board is about 12.5mm x 15mm, slightly larger than a stock DIP8 single opamp.

The preliminary parts list (subject to change):

Q1, Q2, Q3: 2sk209
Q4, Q5: BC847BPN dual NPN/PNP
R1, R2: 150R
R3: 470R
R4, R6: 2K
R5: 150R
R7: 33K
R8: 30R
C1: 15pF
D1: BAV99
 

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Here's a pic of the first prototype of a folded Kaneda-style Class-A opamp in DIP8, all-SMD components. It uses the same topology as the schematic in post #107, but the LTP is a BJT pair like the BC850c or MMBT4403. The board area has been reduced to about 11mm x 14mm by removing unused pins 1 and 5. A rail-to-rail bypass capacitor in 1210 size is installed on the lower layer.

The first prototype is a proof-of-concept test unit which works fine as is, but changes may happen to the values of actives/passives after experimentation.

The two unpopulated SMD locations at the top left are the Miller compensation network from the output to the compensation node, which is also brought out to pin 8, so it can be externally-compensated - for instance, when used as the opamp module in a Mauro Penasa MyRef power amplifier in place of the default LM318.
 

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Here's the schematic and layout of a folded Kaneda-style discrete opamp, with currently-available SMD parts. The board is about 12.5mm x 15mm, slightly larger than a stock DIP8 single opamp.

The preliminary parts list (subject to change):

Q1, Q2, Q3: 2sk209
Q4, Q5: BC847BPN dual NPN/PNP
R1, R2: 150R
R3: 470R
R4, R6: 2K
R5: 150R
R7: 33K
R8: 30R
C1: 15pF
D1: BAV99

Having Q3, Q4 and D1 and the compensation does not qualify it as Kaneda in my opinion.
I would be interested if you try a second experiment with the stuffing of the schema with a resistor long tail.
 
Having Q3, Q4 and D1 and the compensation does not qualify it as Kaneda in my opinion.
I would be interested if you try a second experiment with the stuffing of the schema with a resistor long tail.

It's a folded-Kaneda variant, not the original Kaneda with a differential VAS. It's possible to omit Q3 and jumper its source to drain with a zero-ohm resistor, and I'll try that later. However, the THD20 was a bit high in the sim with a pure resistive current source.

However, you're correct - the sonics of the resistive LTP are better than the one with a high-Z CCS, because of the tanh-character of the resistive LTP. That's one of the strengths of the Melcor 1731 discrete opamp - that's broadly a Kaneda with an additional Class-AB output stage.
 
Hello,

I throw an old topic because I'm currently working on a BOM of the Kaneda preamp and I am looking for the differential input transistors including 2SK30.
I've found the Interfet firm which is manufacturing Jfet for audio applications.


There is IFN860 in range Low Noise Audio, a dual N channel JFET, which looks pretty good on paper. The interest is not to bother to match it with another JFET since it is double:
InterFET Corp. Page Selector - IFN860 Datasheet

They have many references in range Low Noise preamplifier:
InterFET Corp. InterFET AppSelector ... Amplifier /

And others in the category Audio Amplifier:
InterFET Corp. InterFET AppSelector

Do some of you know these JFETs? Are they well suited to a Kaneda preamp? Which references would you advise me?

Thank you in advance for your returns.

Aurélien
 
Hello.I am going to build the Kaneda line preamp as shown here in the schematic i attach but i have some questions.

1)Does T6 have to be in thermal contact with T7 and T8 with T9?
2)Any guide about adjusting the two trimmers VR1 and VR2? VR2 is used so as to have 0.6V at T8 and T9 collectors and about zero offset at output?What about VR1?
 

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Hello.I am going to build the Kaneda line preamp as shown here in the schematic i attach but i have some questions.

1)Does T6 have to be in thermal contact with T7 and T8 with T9?
2)Any guide about adjusting the two trimmers VR1 and VR2? VR2 is used so as to have 0.6V at T8 and T9 collectors and about zero offset at output?What about VR1?

Answer to no.1 in attached pic.
From Kanéda
 

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Hello.I am going to build the Kaneda line preamp as shown here in the schematic i attach but i have some questions.

1)Does T6 have to be in thermal contact with T7 and T8 with T9?
2)Any guide about adjusting the two trimmers VR1 and VR2? VR2 is used so as to have 0.6V at T8 and T9 collectors and about zero offset at output?What about VR1?

I built this preamp.
If you want a regular preamp you only need to use half of it. If you want a preamp with a phono preamp that when you use the whole circuit you posted.
I used for a thermal couple T6 to T7, T8 to T9. I did not build the phono preamp. I used to have the layout, I did some search so I can share it with you I did not found. I built my long time ago at least 13 years ago. I found all the info from a French website.
It is a good preamp but you will have to take your time to select the right components after your taste.
Greetings
 
Hello.I am going to build the Kaneda line preamp as shown here in the schematic i attach but i have some questions.

1)Does T6 have to be in thermal contact with T7 and T8 with T9?
2)Any guide about adjusting the two trimmers VR1 and VR2? VR2 is used so as to have 0.6V at T8 and T9 collectors and about zero offset at output?What about VR1?

I have no experience with this particular implementation, but it's a very standard topology, so:

1) Yes, it helps a little with the DC offset drift at the output.
2) VR1 is used to adjust the balance of the differential pair in the 1st stage; it has effect on the offset, and also even order distortion. VR2 is to set the standing current for the 2nd stage; it too affect the offset, so the adjustment procedure is interative. I'd suggest VR2 first, then VR1, then back to VR2, and so on.

You may want to know this is a very old version; Kaneda has moved on to very different type of circuits, some of them use pentodes.
 
Sorry, the latest info I have is from a French magazine, La revue du son, special issue, June 1998, 20 years ago, paper only of course.

The phono stage uses 2 EF86 pentodes with the RIAA network in the feedback loop. The line stage is hardwired to the phono stage; it has a ECC81 diff pair input, another 2SA1967 differential VAS, and an SEPP with an ECC82 as output stage; there's a serial feedback loop also used for gain control. A very strange animal if you ask me.
 
Thank you all for your advice.I am planning to build the preamp stage and not the phono stage. For T8-T9 I will use KSA992FTA and for T10 i will use KSC3503D.Any recommendation on other possible alternatives?For T8-T9 i also have BC560C,BC556,KSA1015,2N5401,2N3906 and for T10 BD139,2SC4793,2SD669A. One more question ..Is a DC blocking capacitor needed at the input?I was thinking of using a 2.2uF Wima.
 

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