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Saturday, October 22, 2016

Music : Yello, Toy


Being a fan of Yello since the 1980ies, I had to get their new album as soon as it was out. It is called Toy, and deserves a quick review.

It took them about seven years to release a new album after the last one 'Touch' which came out in 2009. It is Yello's 13th album. Being in the music business since the late 1970ies can they keep up with the high expectations their fan base has towards a new album?

Most Yello albums are both very different from the previous releases yet carry the typical sound signature of the Swiss duo which is easily recognised. The first track of Toy is very unlike Yello. It reminded me of typical synth music from the 1970ies. It sounds a lot like Jean Michel Jarre. Which was a funny coincidence because just a few days before I pulled out Jarre's Oxygene and blasted through both sides. I wanted to see how some old electronic music sounds through the ultimate phono stage and ultimate line preamp (it's amazing what this combo picks out of such old records). So it seems Yello paid an homage to Jarre with their intro called 'Frautonium'. They are also ending the album with such a track.

All in all the music on Toy is rather slow and mostly dominated by Dieter Meier's typical narrative style of singing. And of course Boris Blank did his part with his amazing sound creations and samples. As on many other albums there are guest musicians. Most notably Mahlia who sings in some newly interpreted titles from her album 'Convergence' which was produced by Boris Blank.

Yello reuses a lot of material from their own previous work and also from Boris Blank's Electrified. At first listen this can appear as some lazy rehash of old material, but it all has a fresh touch and does not disappoint. They not only pay a homage to Jarre but also to themselves.

The track 'Star Light' also reminded my of some song I new. After a while I realised which one it was. The base line, guitar and melody seem to be straight of the late 1990 hit 'Bakerman' by Laid Back.

The title 'Magma' and 'Toy Square' on the last side carry many sound elements as found on the Yello album 'The Eye'.

Did they overdo the sampling and quotes from other albums? Laziness or homages? I go for the latter since the album is great. May be not one of their best releases but special nonetheless.

Recording quality is superb as is usual with Yello albums, and it is available on vinyl. My copy has some surface noise on some tracks but otherwise appears to be well pressed. Maybe the spare copy I got is a bit better.

If you like Yello, get the vinyl and savor it!

Best regards


Sunday, October 16, 2016

The Ultimate Phono Stage - Part 4


As promised in part 3 about this phono preamp, here some more photos and some sound impressions.

I have been living with this unit for some time now. This helps to get a good feel for it's capabilities and is better than writing in the first excitement when a newly finished device is used for the first time. Especially when only the finest parts and tubes are used as in this one, there is quite some expectation bias.

So can the use of silver transformers really improve upon the already magnificently sounding copper version?

Yes, absolutely! The improvements are similar as heard between the copper and silver versions of the line stage. Especially in combination with the matching ultimate line stage, this is a revelation.

Please forgive the ranting and keep in mind I am building these preamps for a living. So judge my impressions accordingly. Whoever is interested can have a listen to this at my place to get his own impression.

The total absence of capacitors in the signal loops enables these to dig out details from the recordings which have not been apparent before. Tiniest details in the background become visible. And this without distracting from the musical flow. It just adds to the ambience and realism of the presentation.  Voices are simply life like. The nuances and especially decay of each tone is extremely well articulated. A curious side effect: I suddenly also heard flaws in some recordings which I was not aware of before. Like pre echoes from the master tape. Such things are audible in any good system, but I am hearing more of these things now than before. Also on some tracks I heard a slight hum which first disturbed me because I thought something is wrong in the system, only to realise that it was on the recording and it faded out at the end of the track. Now this might seem as a disadvantage, but once realised what it is it didn't spoil the enjoyment. The beauty of the recording is still there, even if it is a mediocre one. This combination of phono stage and line stage is brutally honest.

There is simply more of everything and the records are even more joy to listen to than before. Bass tones are more defined and even the lowest bass notes reveal all the subtle details in the structure of the overtones. Many many shades of dark brown, grey and dark blue, never dipping into an artificial blackness. Just how I like it.

Enough of the ranting. This does not make the copper version a worse performer than it was before, or the single ended variants. They are all fine units and I can happily live with them even after I heard this all silver combination.

Here a view of the back side:

XLR and RCA in and outputs for maximum flexibility. Switches for selecting in and output modes.

Best regards


Tuesday, October 11, 2016

The Ultimate Line Preamplifier, Part 5


The fully differential ultimate line stage with all silver transformers is more popular than I ever expected, despite the high cost due to the many silver transformers. Here is another one just finished:

Two more are in the planning and one of those will finally remain in my own system. 

This one uses the same color combination as the differential D3a phono with which it will be used.

The sound impressions are still the same as from the last one. So I won't repeat that. You can read about the sound in part 4.

Before the owner of this line stage picked it up I had the chance to use it together with the recently finished ultimate, all silver EC8020 phono.

I'll write about that in the  next post about this phono stage. Stay tuned!

Best regards


Wednesday, October 5, 2016

The Differential Power Amplifier - Part 2


A quick update on the differential (push pull) amps.

The first mono amp and it's power supply are completed and went through some bench tests. This is the 'naked' amp section:

Lot's of iron and absolutely no capacitor at all in the signal chassis! As can be clearly seen in this shot from the side:

Power output is a solid 15W.

The power supply section of course has some smoothing caps:

Filament supplies on the bottom and high voltage supply above.
Another photo of the signal section:

Once the second channel is complete listening will start. Measurements are promising. 15W of deep Class A sound. No capacitor colorations since there are simply none in the signal path!

Best regards


Wednesday, September 28, 2016

Tube of the Month : The 6DE4


For this months tube presentation I dug out another TV damper variant. As readers of my blog know, these are my favourite tubes for power supply rectification. TV dampers are still largely overlooked and deserve more attention. So lets have a look at the 6DE4.

TV dampers are very rugged, can withstand high peak inverse voltages, have high current capabilities and generate next to no noise. And best of all they are cheaply available in abundance.

Since their primary use was for television sets they have been produced in extremely high numbers and were made in a large number of varieties to cover different needs. The 6AX4 is good enough for most audio applications. If higher current is needed there are types like the 6AU4, 6CJ3 or 6CG3 and others. The higher current capability comes at the cost of higher heater power. If something in between the 6AX4 and the 6AU4 is needed, the 6DE4 fits the bill. It is a bit beefier than the 6AX4 at a moderate increase in heater current. It needs 1.6A versus the 1.2A of the 6AX4. Still less than the 1.8A of the 6AU4. I already covered the principle of operation of TV damper service in the 6AU4 article, so I won't repeat it here.
Many tube amplifier builders might see it as disadvantage that two of these are needed for a full wave rectification. But I think their superiority over classic rectifiers outweighs that. If a full wave bridge rectifier is wanted (as I use in most of my designs) nothing beats TV dampers. For a full set of technical information please refer to the data sheet. During the high time of TV dampers many new types got registered with very similar specs. This was maybe because of patent issues or tube manufacturers wanted to push their own types. The 6DE4 has an almost similar twin in the 6CQ4 (see data sheet). During the end of the tube era it was common practice to stamp tubes with several designations of types which are close. This was also common practice with the 6DE4 which you will often find with both designations. The RCA30 manual even lists them under the dual name.

Lets start with some photos of RCA 6DE4s.

An older type with full base and the classic RCA box.

A more modern type with 'coin base':

This one has both designations 6DE4 and 6CQ4:

Some details:


The top:

The insulation spiral around the heater is responsible for the good insulation to the cathode:

As most manufacturers, Raytheon produced variations. Here a long and short bottle in comparison:

An older Raytheon:

Sylvania also made these in a number of variants:

Full base with red printing on the tube:

Later version:

The top:

Close up:

Sylvania coin base with dual type designations:

Another one:

Tung-Sol 6DE4:

Zenith in old style box:

And a newer one:

This one was probably rebranded by a store:


General Electric:

6CQ4 and 6DE4 designations also on the base:

GE in military packaging:

Canadian GE:




IEC a supplier of spare parts bought tubes from major manufacturers and rebranded them:

This one lacks the insulation spiral between heater and cathode as other TV dampers have. Makes one wonder if it still has the same high voltage ratings:

Another version by IEC:

This one apparently made in Japan.

This time with the proper insulation spiral:

And lastly Philco:

After the surprising results of widely varying heater currents found in the 6AU4, I also measured some of the 6DE4s. They were mostly well within specs:

Except for the IEC in the smaller bottle which only measured around 1.2A:

Probably just a 6AX4 labelled as 6DE4!

This concludes the presentation of the 6DE4 I hope you enjoyed it. Stay tuned for more TV damper talk in future posts!

Best regards