DIY Kondo M7

Click pics to enlarge. PS Audio Lambda and Ultralink II. Clone Kondo M7.

Virtual Home Visit (12): DIY Galore

Modified August 7, 2020: The host actually designed ALL his PCBs; none from outside suppliers.

Our yumcha friend Thomasfw is a DIYer of some repute. Like many DIYers, I think he derives more pleasure from making things than listening to them.

If you look at the pics, you shall see work of a high standard. And they are not cheap because they use boutique parts like M-cap and Leader volume control from hificollective. ALL of the boards are designed by our host himself (he is in the industry!)

Clone Kondo M7s
Actually you may have read about its prototype before. It is buried deep in this article (roll down to the David vs Goliath section). I quote:

Surprise! David vs Goliath? As it happened, our yumcha friend davewong had been building a Kondo-clone preamp based on the very simply laid out boards by thomasfw. Since it is said to be a Kondo-clone, I expressed an interest to hear it (a very rare occurrence). Suffice to say, davewong geared up and had the prototype ready that day (click on right pic to enlarge), so we took it along to Jules. The DIY preamp employed 6X4 rectification and MOSFET regulation. For the line section, the two triodes of the 12AX7 were coupled and output was cathode follower. No exotic components were used - Dale resistors and Wima red caps for the line section; Philips caps for the power section. Sound The Kondo clone actually sounded quite decent. It seemed to be modern sounding, with a surprisingly fast leading edge (methinks faster than the Koda). Immediately, there were more air and a deeper soundstage, and the front corners were better illuminated. With the jazz CD, virtues were more split: the percussion had better rhythmic expression and exactitude with the Kondo clone; the saxophone and guitar sounded much fuller with the Koda - a surprise as usually one would expect the reverse. A Little Tube Rolling As there were Europhiles present, Valvo long plate's were swapped in for the RCA (D getter, grey plates). Immediately, the saxophone and guitar sounded much fleshier and much closer to the Koda, but at a cost - the percussion lost almost all of the snap (a price I personally would not pay). The Votes Though still a flawed prototype, some of us preferred the DIY tube preamp, but pluto, a DIY man, admired the Koda. As you see, it was not quite a David vs Goliath scenario. Suffice to say, both the DIY kit and the solid state Koda met with our approval, and (except for pluto and maybe jules) this is a rather hard-core tube crowd! After this, we reconnected the Koda and listened to analogue playback.

Detour: Kondo Clone vs Kondo/Audio Note Japan M7 After I got home, I actually briefly compared it to my own Audio Note Japan M7 (the one in the pic). Both are quite neutral sounding so it is hard to say whether they sound alike, but the challenger was obviously a little on the lean side and rhythmically a little too insistent, without the M7's subtle and articulate nature. Still, a respectable showing!

Kondo M7, Phono section derived from ANUK. ChineseInput and Output Transformers, 

4 for about USD 400. Phono Board Self-drawn.

Dual Mono Power Supply derived from Kondo M1000 

Small Listening Environment

Another Clone M7 next to SE EL84 with Tango Output Transformers

Inside the M7 Line

Inside the SE EL84