Beer of the Bass Posted April 25, 2019 Share Posted April 25, 2019 (edited) 70s Dynacord Eminent II amplifier. This is a valve powered amplifier originally intended for PA use, using a pair of EL34 run at high voltages for a rated output of 80 watts. In stock form the amp had a four channel transistor preamp, and was built to be very clean and linear sounding. The perspex front panel has green lights behind it, so it's quite stylish in a kitschy way! I have modified the amp by removing two of the transistor preamp channels and building a preamp based on a late 60s Ampeg B15n using a 6sl7 valve. This is the four black controls on the right of the front panel. I used a high voltage FET stage to match the output and impedance requirements of the 6sl7 preamp to the power amp section of the Dynacord, but the signal path for this bypasses all of the original transistor preamp circuitry. I have also rebuilt the power amp with new filter capacitors and a new pair of JJ E34L valves, and set the bias to suit them. The two original input channels and their master volume and EQ are still functional too. With the Ampeg style preamp, it provides a very pleasing classic bass sound, and would be a good addition to a retro-minded studio or for moderate volume live use. It doesn't provide heavily overdriven sounds, but with the preamp gain turned up it does a great subtle breakup that thickens up the sound nicely, and it also has a nice range of clean bass tones. It's quiet in terms of background noise too. It's relatively compact for a valve head, and comes with a well used but useful ABS flight case to carry it in. It has impedance selectors on the back panel to run 4, 8 or 16 ohm cabs. Edited January 11, 2021 by Beer of the Bass SOLD 1 1 Link to comment Share on other sites More sharing options...
Beer of the Bass Posted April 25, 2019 Author Share Posted April 25, 2019 Additional pictures showing the case, back panel and a crack at the back corner of the plastic outer which is taped over. Link to comment Share on other sites More sharing options...
CalDeep Posted April 29, 2019 Share Posted April 29, 2019 Is the DI still functional? Link to comment Share on other sites More sharing options...
Beer of the Bass Posted April 29, 2019 Author Share Posted April 29, 2019 (edited) 2 hours ago, CalDeep said: Is the DI still functional? It doesn't have a standard XLR DI output - the 1V line level output on the back panel is a summed output of the original preamp channels, and is on an obscure 3-pin DIN connector so I haven't tried it. It appears to be intended for connecting other Dynacord gear of the same era in a slave setup. But the 6sl7 preamp channel that I added is mixed in after this stage, so wouldn't be present on this socket anyway. For a DI output from this head, a speaker-level DI box connected to a spare speaker output should give decent results. Edited April 29, 2019 by Beer of the Bass Link to comment Share on other sites More sharing options...
Beer of the Bass Posted May 11, 2019 Author Share Posted May 11, 2019 Bump with a little video demo. received_316504045692220.mp4 1 Link to comment Share on other sites More sharing options...
Happy Jack Posted August 10, 2019 Share Posted August 10, 2019 I used to love those Dynacord valve amps. I had several vintage ones from the early 60s, all built (as you'd expect) like a tank. 1 Link to comment Share on other sites More sharing options...
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