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constructionPlease note that this website is still under construction!


Redesign of the Chinese "MUSIC ANGEL 845"

You can download the fully revised article (V4.0) as a PDF file.
The full schematic of the sound stage to the article (V 4.0) can be found also here, including the power supply.
The modding possibility of the B1+ power supply (according to the idea of Mr. van Hall) is shown as a schematic (OLD -> now substituted by the gyrator version).
A supplement was made in V4.3, which includes a gyrator stage per channel. This gyrator connects to the idea of Mr. van Hall, improving its effect while no iron-choke is used. It is substituted by this gyrator circuit. The results are much better than achieved by an "iron"-choke.
Some pics of the modified MA845 of a friend can be seen here also.
Data sheets of the NOS AMPEREX 845 and RCA 845 are here.
Data sheets of diode families GP-600  and 1N540x are here too.
The schematic and an article about input connection via a balancing transformer can be downloaded here.
Finally I wrote an article about putting the MA845 into service, resp. "into action",  after you finished all the modding of the amp.
Pls. keep in mind, that I shall not accept any claims nor be responsible for any injury or damage, implied or not implied, from the usage of this paper!

“MUSIC ANGEL 845” - v4.0

full schematic with gyrator v4.3a

schematic power supply add. choke v4.3

B1+ Gyrator circuit

Binder B1+ Gyrator circuit

Gyrator spreadsheet

IRFP450 datasheet

some pics


RCA 845



“Balanced Input”


Tube pre-amp "TEQUILA"

This project contains a complete tube preamp including phono and line-stage.
You can download the complete schematic as PDF.
I used ÜP 2687M (Pikatron) as a step-up for MC/MM. Its datasheet is enclosed. (Could also use DIB-110
reversed, from Monacor).
You also find a schematic for a standalone step-up transformer unit, using this DIB-110.
A parts definition is also attached.

Some pics of a partly finished TEQUILA to let you see in which way I mount the parts of the unit. Last pics show the separated supply unit.
A pic of my own finished "Tequila" tube pre-amp.
schematic TEQUILA Mk 1 tube
parts definition
MC/MM step-up
Finished MC/MM step-up
My Tequila

Berechnung von Tonfrequenzübertragern

(Calculation of Audio transformers)

This is a basic tech article I wrote some more than 40 years ago and which includes all the equations resp. formulas for the calculation of tube-output transformers (OPT) as well as all other kinds of Audio transformers.

There is the original German version and a newer English translation.

This translation correlates with the EXCEL-sheets made for the actual calculations. See the numbers for the used equations.

I put here too a table showing all necessary data of European and M- and EI-cores.

If you are interested in testing and taking electrical measurements of SET-tube output transformers, you can download a simple instructional drawing.
Attention: this is available in German only!
Die Berechnung von Tonfrequenzübertragern (in German)

Calculation of Audio Transformers (in English)


Data of M- and EI-cores

Test of Audio transformers (hand-drawing)
Aging tubes artificially

Here you can download a PDF about the conditioning of newly manufactured tubes. Please note the exclaimer and you should only use types of good manufacture.
A word on brand new tubes, to give them NOS performance.

A Tube-Delay

Here you can download a PDF about a versatile tool containing a 2x 20 seconds digital delay, which may be used for the pre-heating period plus an extra muting delay.
Binder Tube-Delay

Because I received many questions about useful speakers for SET-A amps, I wrote this new article. you can download this article from the link at the right.

Choosing the right link will download a ZIP-file showing a detailed view of my fullrange horn speakers and some pics showing the way they were built.

"A Word about Speakers and SET-A Amps"

"My horn speakers"
“FETishizator” a CD output stage
You can download the newly revised article (V3.0) as a PDF file.
Additional information about the used JFET (BF245), the MOSFET (BS170) and the Darlington transistor (BD651) can be found within the article.
There was a mistake, concerning the I/U-conversion when using TDA1541, which is now corrected (THX to Mr. Darko Marijan from Sweden).
A binder with all materials for version 3.0 (schematic, PCB, parts) can be found here too.
I received many eMail questions about the “RF-Trap”. You can download an additional article on this topic here.
FETishizator V3.0

Binder FETishizator


“DIGI-FETishizator” the best coupling S/PDIF.

The hand-drawn schematic is here as PDF file for download. For further information please refer to the LAMPIZATOR website.


“A general view at STC”

This is a basic explanatory article I wrote because I received many eMails about the HOW and WHY of this new technology. You can download the article as a PDF file.
Basic STC

“Preparing Laser-Disks” for best operation and performance

This is again a basic explanatory article I wrote because I received many eMails on the question of reliability of CD enhancement-gear and -processing. I tried to investigate the web but found out, that the whole matter is penetrated by mysterious believing and commercial nonsense. Only a few ideas are physically based. I tried to give a simple method and you will be astonished on the
big improvements.
You can download the article as a PDF file.

Preparing CD for best performance