Hi everybody, and greetings from a new member and enthusiast.
Years ago I imported several kits from Velleman Netherlands, amongst them a K4000 Valve Amplifier, a K4100 Digitally Controlled Preamplifier and a K 4500 Digital Synthesizer FM Tuner. Unfortunately, I never found the time to assemble the kits, until now.
Starting with the task I found out that the available assembly manuals are incomplete. There is no illustration available. The newer version K 4040 -is on the web, with illustrations and schematics.
Is there anybody out there who can help me with more complete literature?
The supplied manuals are the only manuals available. They contain all necessary information that you need to assemble these kits. As these are ‘vintage’ kits, their manuals are not as graphical as today’s kits. If you have any specific problems during the assembly, please let us know.
Hi Helping Hand,
the amplifier is almost ready to be tested. But now I am having a basic problem:
The Power Transformer (the one in the middle) seems to be of the most impossible type for use in Brazil with mains of 110V. According to the manual it seems to be the type 3 with a brown, a pink and an orange wire on the secondary coil.
Did I understand correctly and the description in the manual is for a type 2 transformer with 2 pink wires?
Is there any other solution for me than the exchange of the power transformer from type 3 to type 1 (with 2 brown wires)?
The next doubt:
Checking for short circuit on the amplifier boards I get a reading of 435 ohms on both boards. Does this seem to be correct?
Thanks on beforehand for your help, I will certainly be back soon with more questions.
The supplied transformer is 220-230VAC only.
(primary: brown-pink: 220VAC, brown-orange: 230VAC)
You will need a step-up transformer (110 to 230VAC) in order to be able to operate your amp.
It will have to be rated for at least 500VA
Regarding the short circuit issue, how and where did you measure ?
I measured as instructed in the manual, between the 6,3 V terminals, before assembly and connecting the 6,3 V supply.
The 435 ohms you measure is correct (2x220 ohms in series to make the filament voltage symmetrical with regards to ground, to avoid hum).
Hello, I have a question about my K4000 amp.
I have a problem with the 6.3VAC clamps on my left channel.
6.3VAC in
1 2 3 4
-f2 - f1-
At point f2 i measure a good sinus of about 6.3V, at point f1 I measure a signal vaguely resembling a sinus (very irregular) at a much lower voltage.
I tried the powersuply of the right channel on the left board, but it gives the same results. Could someone help me a bit futher along the way of resolving this puzzle?
Yours Truly,
Erwin Tromp
The Netherlands.
It looks like there is an interruption somewhere either on the board or in the secundary winding of the transformer. Check continuity with your multimeter.
The problem seems to be with the left board. I used both powerconnections from the transformer on both boards and I only see an interuption on f1 leftchannel. It’s present from the tubefeet to the clamps.
It is unclear to us what you mean by ‘clamps’. Please elaborate.
Sorry, wrong translation. Clamps = The 6,3VAC in terminal
If there is 6.3VAC present on the connector where the transformer secundary is connected, but not at the tube socket, then problem is most likely caused by the wiring.
Maybe the problem is the terminal itself. I’ll take a look at it.