Manley Labs AMPLIFIERS Overhead View, Input, Bal/Unbal, Fuses, Iec Mains, Output, Switch

OVERHEAD VIEW

	INPUT	INPUT	BAL/UNBAL.	FUSES:	IEC MAINS
OUTPUT	XLR	RCA	SWITCH	B+ MAINS		IN

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EL34s/KT90s

12BH7/ 12BH7/

6414 6414

12AT7

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EL34s/KT90s

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Tube Location & Type

OUTPUT TUBES: 10 x EL34 (250W) or 10 x KT90 (500W): The EL34 types we recommend are the Sovtek EL34G, EL34G+, EL34WXT, Electro-Harmonix EL34EH or the JJ EL34GT as supplied to us by our pals at Groove Tubes. For the 500W model, we recommend using the KT90EH by Electro-Harmonix. These have been proven to be the most rugged, reliable, and best sounding for these amplifers and we strongly emphasize that only these types should be used in these amplifiers. The MANLEY NEO-CLASSIC 250 & 500W MONOBLOCKS have been thoroughly optimised around these tubes. Use of unapproved tube types can and will void your warranty. We have selected the tubes for equality of current draw in our custom-built computerized tube tester for each of your monoblocks . Although each tube bias can be individually adjusted, "matched" tubes as we have selected are thouroughly beneficial to the amplifier's performance.

DRIVER TUBES: 2 x 12BH7A (250W) or 2 x 6414 (500W): We use the Yugoslavian Ei 12BH7 for the driver tubes in the 250s these days. They seem a little better than the more easily available Russian Electro-Harmonix 12BH7EH's. Good luck trying to find any American 12BH7A NOS these days.... For the 500W model, we

use 6414W tubes made by GE. In both models, each tube handles a phase and each tube's dual triodes are paralleled up. So selecting for triode-to-triode matching on each of these driver tubes is completely unneccessary.

INPUT TUBE: 12AT7WA (250W/500W): The 12AT7WA has several equivalent numbers: 12AT7, 12AT7A, 6201, ECC81, etc. Any of these types may be used. We have selected this 12AT7WA very carefully for noise, microphonics, and constancy. We like the large plate Ei Yugoslavian tubes for this application. The two triodes are paralleled so matching of the two triodes is not necessary. Just select for low noise examples.

Replacement tubes of premium quality tested for best performance in this amplifier are always available from MANLEY LABORATORIES. Fill out the PARTS ORDER FORM on our website if you'd like to order some spare tubes or fuses.

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