Hand Made Perfection
newly received or noteworthy information, esp. about recent or important events : I've got some good news for you.
Compiling Parts For A Single Loudspeaker For The Monophonic Setup
Among the parts found and collected is a JBL2420J HF driver that will be used with the JBL2370A horn. The crossover will be a second order @ 900Hz cutoff frequency. Still missing is the JBL2206 12’’ woofer and the vented box.
How To Turn A Stereo Cartridge Into A Monophonic one
A trick that I picked from my MW radio days is how to turn a stereo cartridge into a monophonic one.
Well it is pretty simple, you just have to short the cold right channel out to the hot left channel out, then you connect the hot right and the cold left to your mono amplifier/preamplifier.
Don’t forget to adjust the R-load accordingly.
So Long Mr. Sakuma
It was more than ten years ago when I was scanning the internet to find something interesting and give a new meaning to my life when I stumbled upon Mr. Sakuma’s site.
I was surprised by what seemed to be a pile of junk and I decided to revive my building skills for tube electronics, skills I had left aside for ages.“If this guy is successful I will conquer the world” pleaded without much thought.
I don’t want to be misunderstood as I found extremely smart his outrageous electronic designs but the realisation was looking a bit like a rat bike.
It took me some time to realise the value of these outrageous realisations of tube amplifiers, where symmetry, order and beauty were extradited to Hades. The rebellious mind of Mr. Sakuma was revealed to me when I started trying to understand the “Japanese” way of life, where even forests are clean, tidy, and the trees are in order.
Sadly today the tube electronics society lost the last inventor of alternative designs.
As the monophonic ‘’RCA’’ phono preamplifier would feel lonesome I had to pair it with a mono ‘’vintage’’ turntable.
The choice was easy as a Garrard 401 was my favourite pick.
Now that the digital audio technology has reached its peak and anything sounds like everything, I felt the urge to step back to the day mono ruled.
So much technology, so many developments since the monophonic days and still most MP3s and Youtube videos sound like a coffee grinder.
Well, besides all that, stereo always got on my nerves every time I would listen music in a car or in a bar, as I had half of the music, usually the half that was on the speaker, near to me. Not to mention that most of the times I listened to music I was engaged in at least one more activity, sitting or standing far away from the stereo sweet spot. Not that I twerk but an X-lent example that music is a multi level fun, is Michelle L’Amour performing Beethoven’s 5TH symphony.
Being pined down and just listening to music always seemed to me like the clockwork orange torture.
The idea of building this mono phono preamplifier that is based on an old RCA schematic I came across in the net was not hard to resist. The schematic includes four different equalisations for old LPs.
Back to Mono?
As much I hate to scold there are things that have to be said.
I can understand and accept those people that collect records as others collect stamps, matchboxes, mugs or other useless stuff. What I do not comprehend is the urge of those misinformed trending hipsters that spend a kings ransom for turntables and dedicated preamplifiers for a troublesome, almost useless medium, as vinyl.
I do recall the days we used to send the master tapes to the record plant for production and what we got back (white label, test pressings) was something a lot different to the original recording. I do also remember cutting the lathe several times till we could compromise and get an acceptable result. Needless to mention the narrow frequency response, the limited headroom and the high surface noise. All these make me believe that it is totally stupid to resurrect a medium that is so limited and has nothing to do with ‘’high fidelity’’.
The problem is even greater for the new production of vinyl records as they are mostly cut with some eastern block leftover lathe cutting machines, and then print in 200 plus grams records with superficial grooves. Those unacceptable records have grooves that are thiner than the scratches in my favourite well played records. (Thin grooves means lower volume, easier destroyed records and higher noise to sound ratio).
And as if the neo-vinyl curse was not enough there is another trend for those with deep pockets and their mouth in the place of their ears. That moronic trend is the lust for open reel tape recordings. I was always wondering what is the source of those recordings, as some of them are from the sixties and seventies, and how they are mass reproduced to open reel tapes.
Here I have to mention that the problem with the tapes is that they have limited lifespan and that they self demagnetise and rot.
They need a storage environment that is controlled in humidity and temperature, away from strong magnetic fields, and to be kept tails out for the print through phenomenon. Even so they have to be baked from time to time in order to get revived.
These are only the problems with tapes, troubles pile up with the maintenance of the tape recorder/reproducer.
In the good old analogue studios there was an in-house maintenance engineer whose main tasks was to keep among the other apparatus, the tape recorders up and running and in good shape. So think twice before getting involved in the open reel madness.
For sure 9990 is an X-lent step-up transformer for MC cartridges. With a nominal ratio of 1/20 it is a match made in heaven for my DL-103r cart. Neither a correction filter nor a load adapting resistor are used.
Even better, the best future of this transformer is that you don’t have to sell a kidney and half your liver to get it.
For more information about step-up transformers
This is a newly designed preamplifier, constant current source loaded, with a pair of EC8010 tubes. The frequency response measured is dead flat from 10Hz to 36Khz. It is of para-feed design, the output transformers have a 5/1 ratio with 15KΩ primary and 600Ω secondary. This new improved version employees a pair of SOWTER 1010/1701b transformers for peace of mind and for better lower end. For more info click to link.
A pair of second Order Linkwitz-Riley power filters @ 10Khz were built for the Fostex T90A tweeters to compliment the FF165WK bass reflex speakers. More information in the Paraphernalia page.
A new pair of bass reflex loudspeakers were build in a 18 lt. enclosure tuned @ 54Hz .
Here is a picture of one loudspeaker over the meter bridge of a mixing board next to Yamaha HS8 self powered monitor .
More information in the Paraphernalia page.
The new amplifier named Aura is finished and tested It uses 2A3 output tubes and E86C drivers .
Click to link and discover how m-amplifiers are built.
A commission on a shoestring was the building of a pair of bass reflex loudspeakers employing the Visaton BG20-8 drivers in a 30 lit. enclosure tuned @ 40Hz.
For more information please click to link.
A new , parallel feed , tube amplifier employing the 300B as output tube.
There were no shortcuts for the components used in this amplifier , on the contrary it is a ridiculously over-designed and heavy amplifier for its 2 X 5 watts output .
Heavy is also the CO2 footprint of the amp and it certainly does not conform to DIN.
I was always skeptical about the products from behind the former iron curtain as if I were to buy me a car I would never but never get me a Scoda, Wartburg or Volga. You might say tubes and cars have nothing in common but let me note that the production mentality is the SAME.
To cut a long story short I did an a/b/….n test with several 2A3 tubes and the winner, hands down, was the Slovak JJ 2A3 that still has to prove its value in time depth.
The tubes under test were : CVC, Fivre, Sovtek. Shuguang (Small and Large glass envelope), Emmision (solid and mess plate) and of course the JJ 2A3.
In my opinion the CVC, antique Fivre and Sovtek are good enough for target practice. The Shuguangs are acceptable in case you like harsh high frequencies.
In the league of the big boys, Emmision and JJ, the JJ sounds fuller with excellent lows and airy, clear highs. The second runner up was the Emmision mess plate with a more ‘‘constrained’’ smooth sound, all of the big boys have thick crystal glass envelop as some one would expect from the famous glassware tradition of Czechoslovakia.
Please don’t forget that the opinion about those tubes is clearly subjective but based in objective study.
NICE PICTURES OF OLD NEWS