Kaan Seler's
Date of "Visit":
08 February 2004



DIY preamp

DIY mono power amp

the bottom view of the power amp


e-mail to:
Kaan Seler

I live in Ankara, with my wife Nilgun and 4 years old daughter Alara, about 4 hours driving distance from where Adnan Arduman lives. I did not have a chance to meet him in person but through his excellent web pages.

I have been audiophile and a DIYer since high school years. I assembled my first system 25 years ago which consisted of a modified Elac turntable with entry level Shure cartridge, home made Isophon coaxial speakers with add on cone tweeter and a home made amplifier.

My love of audio equipment influenced my profession and I became an electrical engineer. Currently I work in defense electronics sector and continue my interest for audio electronics as a hobby. Over the years I have gradually upgraded towards high-end equipment mostly in DIY format.

Most typically, my wife is not enthusiastic about my hobby and any equipment related to it. But I could still manage to put a pair of Dunlavy SC IV and not so beautiful looking electronics in the main living room and allocate another room for my DIY projects.

Eight years ago, having completed many solid state electronics projects, I decided to plunge into a tube amplifier project. This was a 120wpc stereo power amplifier, based on 6550 Svetlana tubes with Ultra linear push pull topology. The end result was dynamic full and effortless sound. More musically satisfying than my Adcom GFA555 mkII monoblocks driving Magnepan 1.5QR speakers. After that I started a design project based on circlotron topology with 6C33C triodes again with plenty of power to drive Magnepans. The project lasted a year with repeated alteration and optimization on almost all sections of the amplifier. The sound was an improvement over the previous design. This amplifier had a better bass control. It is difficult to explain sound with words but the sonic crowdedness of complex passages were simplified and dynamics of individual instruments were increased. The amplifiers are tested against best solid states with true reference speakers going down to 20Hz and results were more in favour of this amp even at low frequencies where solid state has an edge.

Then I have started a preamp design. This was based on mu follower topology with 6CL6 pentode load using 3 sets of parallel 6H3NE Russian triodes. The tubes are equivalent to WE 396A. The sound is very dynamic, open and detailed compared to ADCOM GPA-750.

As an electrical engineer I believe that measurements are almost as important as listening tests and I can predict how an equipment will sound just by looking at measured data (I expect to receive "nice" comments about this statement). I read Stereophile magazine mainly because the equipment reviews are supported by detailed and meaningfull set of measurements..

I believe the sound quality should not be compromised in some areas in favor of some others. Even though I love the sound of single ended systems I don't like to limit my musical selections by excluding large orchestral works etc. I don't like the concept of matching equipment to get an optimal performance.

I prefer digital sources to analog because of the similar reasons. I believe digital sources have better overall sound integrity over analog sources.

To me the term audiophile defines a person who likes audio equipment as much as music, and listens to equipment as much as musical notes. A DIYer audiophile is a person who listens to the equipment even more. I sometimes find this (plus working with lethal voltages) too stressful to pursue as a hobby, but after finishing a product the satisfaction you get is worth it.

I prefer to listen to jazz (75%) and baroque Classical music (75%). I prefer Bach, Handel, Orf, Saint Saens as composers. I admit, I am not a music expert and especially the performances I choose for classical music are mostly based on recording quality. I believe that the recording quality is as important as the system components on the final outcome.

System's Components

CD player:

Audio Analogue Maestro


DIY preamp with SRPP pentode loaded parallel connected 6H3NE tubes using no negative feedback. Mosfet regulated supplies.

Power Amps:

DIY 140Wpc Mono Block Tube "circlotron" topology power amps using quad Russian 6C33C tubes with mosfet regulated power supplies. With direct coupled ECC85 driver and capacitor coupled differential 6H3NE input tube using only 7dB of overall NFB with no frequency compensation. Output transformer is custom designed double C core with interleaved windings.


Dunlavy SC IV


CD to Preamp: DIY Semi rigid coax microwave cable with solid core and shield using Teflon dielectric.

Preamp to power amps: DIY 26AWG silver coated Teflon insulation twisted pair cables.

Speaker Cables:

Bi wire, DIY flat ribbon cables with 26 interleaved +,- wires with 6 ohms characteristic impedance.

Power conditioning:

No external devices. The supply regulators and input mains filtering in my DIY equipment is optimized to the typical mains performance characteristics where I live. I have measured mains voltage variations that it is impossible to be corrected by filtering or using expensive cables alone.

Kaan's comments about his system:

AA: "Kaan, how would you describe your system's sound?"

KS: "The sound is very analytical but detailed in midrange and lower treble but has full body in the lower frequencies with robust extension to 25Hz. (The listening room has 10m by 6m dimensions which supports frequencies down to 20Hz). The upper treble is somewhat strong, giving perception of high detail. System is extremely dynamic. The piano sound is exceptional, female vocals are a little forward, sustained organ notes are well behaved but not over stated as most big speakers. There is bass if it is present in the recording otherwise the sound is lean. There is no softening in the upper bass, but it feels like it is missing some favorable warmth."

AA: "Do you think there is room for improvement?"

KS: "Always. Less accuracy but slightly warmer sound is preferable. The high frequency emphasis and reverberation can be tamed with some room treatment, with approval from my wife of course."  

AA: "Have you got plans for upgrading?"

KS: "I am planning to get a SACD player but lack of availability of decent SACD CDs I am still waiting. Also as a former Magnepan owner (MG1.5QR) my heart is still for the Magnepans especially MG3.6R. If I can get my hands on one in Turkey, that will be a true upgrade. I am also in the process of designing a high power (40Wpc) single ended amplifier. This will be an improvement if I can get SE midrange with decent low and high end."