tag block / board

Using this tag board many circuits were build and tested. Driver circuit is tested with power stage, so we measure the real thing. In technical sense the circuit has to be okay, so circuit is measured and optimized for AC swing/amplitude, frequency response and distortion. Later the circuit will be evaluated in terms of sound. Using this set-up components are easily changed and access for measuring is very convenient.

		First steps - using this tagboard circuit + component values were tested.

A stand-alone variable high voltage supply is used with a stand-alone 6V DC supply for the heaters. In the end a long-tail and a cathode follower measured best, so this would be the base for the new design. And remember one of the design goals is availability of components like the tubes. Also tested are the 6N3P and the 5965 as long-tail, because these are not that widely spread, they were not selected / chosen for the Elektuur/Elektor project/design. Notice: the 6N3P and 5965 can not be used in the ECC83 circuitry. The 6BQ7a and 6N1P were tested and used as cathode follower, also with good specs and sound.

The 5965 is pin-compatible with the ECC83 and for this reason anode resistor and AC/DC parameters are determined for the 5965 as upgrade option; this for the 6N1P and 6BQ7a, both as cathode follower, as well.

driver circuit board

		test driver board - evaluation board of the driver using WIMA MKP10

Using the SLayout program a circuitboard was made and prototype was actually build and tested. No problems were encountered until actually amplifier was build. Because of the few power voltages groundloops were causing hum. The final circuit board does have for this reason separate grounds.

Circuitboard is made in such way that driver and power section can be separate. In this way we are more flexible in set-up. This way of design is also helpful because driver board dimension is 160x100mm (Eurocard) and can be made easily made in the test-lab.

power circuit test board

		overview power section board - original circuitboard is cut in 2 parts for easy set-up

overview

Down here an overview of a complete working mono amplifier for testing purposes, fine tuning and sound evaluation on one single computer speaker. Mono and using such a cheap speaker will provide a very good impression if something has some future or potential or not.

		Overvieuw complete working amplifier one channel - working amp with 220V connection, powersupply and in and output.

ECC83/ECC88 stereo driver for sound evaluatiation

		stereo test driver board ECC83/ECC88 - this board fits the rebuild Electrocompaniet amplifier shown down here for checking sound performance.

Using the rebuild Electrocompaniet amplifier (as mentioned in Nishiki section mod 1) different drivers can be tested in terms of sound, board is made in such way that it is interchangeable with the original set-up using the 6N3P tube [this tube is compatible with the 5670, 2C51, WE396A]. This 6N3P tube is a great little tube with fine overall specs and very good sound, it is also very cheap. You might like to check out Ebay for this.

		Amplifier is using a single 300VA transformer for 2 channels; BH SlitFoil 15000uF are used as PSU capacitors. Please click picture for more details.

final MUGEN board

A professional made circuit board as designed and used for the Elektuur/Elektor project.

		Mugen Hybrid Amp Board