This wonderful german masterpiece from the 1960-ies is a all-tube tape echo machine.

At these days it was impossible to get real echoes without record the signal directly to a tape-loop and play it back a little timespan later.

Before the german company Klemt was overtaken by Dynacord they developed this great machine. It has some predecessors, among them the famost one called the NG51. It's housing and faceplate was golden-colored, so it became the nick-name "The Gold-Cage". The ingrediants are mostly the same ... the E 51 is a typical facelift product to handle customer taste and to fit optically better to Klemts Amplifier series from these days.

There are three tape recordings heads. The recording level for each head could be dialed in with one of the three Potentiometers (1,2,3) on the upper side of the front panel. Any mixture is possible. Playback is possible with two playback heads. The first head is always on, the second one could be activated via a Push/Pull Switch-Potentiometer on the lower side of the front panel. The Potentiometer also regulates the amount of echo repeats. The tape loop itself will be driven from a motor. There are two constant speed's possible or you can stop the tape-transportation if you won't have the echo effect. All active electronic components in this unit are tubes !!!

This E-51 has some faults as it comes to me. Input 1 was complete gone ... only very noisy echoes were produced, sometimes interrupted by heavy and loud spikes. The tolex-case was grey instead of black and was missing glue on many points. The trimmer potentiometers for gain and tone of all channels are very bad ... they worked, but not as good as they should. The magic eye glows only weak ... and the unit needs a fresh tape-loop and a new adjustement.  

Here is a list of everything that was done during this restoration :

- Fresh up the tolex-case and glue the loosen parts

- Get a service manual ... it's really heavy to demount this unit without one :o)

- Demount Preamplifier trimmers for Gain and Tone for CH1 and CH2 and Gain for CH3

- Replace with Alpha Pots on mounting plates

- Replace all internal Trimmers on different locations with Piher and Alpha Pots

- Replace only the leaking coupling capacitors (preserve Mojo ... as much as possible :o)

- Replace the coupling capacitors for the first stage against Phillips Mustard's :o))

- Added additional 100uF filter capacitors for DC stabilization (after some days of playing, I changed this again to only 50uF of additional capacitance. The DC Line was so stiff, that it starts to sounds a little "liveless")

- Change the magic eye against a new one

- Change the tape loop ... after some tries with standard tape I ordered some spares by Bobby

- Adjustements as far as necessary ... partly you need some special equipment to do all adjustements.

In one word ... It sounds wonderful !!! I think this is a result from the full tube design and the unperfectness of the tape transportation. You got two switchable speeds, but they aren't constant. They will have something, what an engineer will call "Wow and Flutter". This is a measurement method to quantify the amount of frequency (speed) wobble during normal (constant) tape transportation. This speed wobble is part of the typical "Mojo" of this piece of gear.

Plug in a Strat, Tele or Les-Paul ... dial in some long echos with medium repeats ... put a little of plate reverb behind it and enjoy ... be sure ... this will make your day :o)