| Author | Message | ||
| Jelle Wiel (jvdw) Username: jvdw Registered: 01-2014 |
Hi All, Nereby, there is a 112RD-100 for sale! This should be the pearl of the Music Man Amps with the EVM 12L speaker, don't you think? The amp is dated on 16 january 1980 and it has EL34-tubes. I cannot find the code of the circuit (GD-1, GD-2, GD-2A) on the amp (Where to find?), but the model chart on this website says the 112RD-100 EVM has 6L6-tubes. Does someone know if EL34-tubes could be the right tubes for this Music Man-model? (Some pictures of the amp and circuit are available on this website: http://www.marktplaats.nl/a/muziek-en-in strumenten/versterkers-bas-en-gitaar/m78 0742487-music-man-leo-fender-112-rd-one- hundred-100w-bj-1980.html?c=8c285449651f a109c354bbabe740c1b&previousPage=lr) Thanks in advance | ||
| Steve Kennedy (admin) Username: admin Registered: 03-2002 |
To my knowledge, the 65 & 100 watt RD/RP amplifiers came with all the tubes used by Music Man over the years of production. The schematics show this clearly and the model chart is somewhat simplified and needs updating in this regard. Production of these models started in 1978 with the first versions that came with 6CA7 output tubes and used a large relay for distortion switching. In late 1978-early 1979 there was a phased change-over to EL34 output tubes in ALL Music Man amplifier models as the supply of Sylvania 6CA7 tubes dried up (they were no longer manufactured). Some of these amps came with the relay switching while they phased in a newer board with electronic switching. For example, I bought a 1978 RD112-65 brand new in 1978 (November) that had the older relay switching but had EL34 output tubes from the factory. The models made from 1980 on had 6L6GC output tubes and this coincided with all the new models that also were based on the 6L6GC output stage design. Each one of these versions can be seen in the schematic package (although almost nothing is dated) and each had a different system board as indicated. The EVM was standard with the early RD100 models but the amps still came in black Tolex. In 1981 or 82, the "normal" models came in black and the EVM models came in the cream Tolex awith balck grill cloth but could still be special order with an EVM speaker in black. Confusing, huh? Amazing what you can learn by studying the schematics, Price Lists and Catalogs! Steve | ||
| Steve Kennedy (admin) Username: admin Registered: 03-2002 |
BTW, your main board in that amp is the later board without the relay. You would have to compare this board to the schematics to determine which newer style it uis but unless there is a tube chart showing EL34 tubes I would guess that this would take 6L6GC output tubes since you have a 1980 date on the board. Steve | ||
| Mike Griffin (mgriffin155) Username: mgriffin155 Registered: 02-2014 |
The trace side of the PC Board should have the GD-1 or GD-2 or GD-2A designation on it. At least my 112-RD-65 does. It says GD-2A on the trace side. The component side has a hand written date 8-12-81 and the number 65. Unfortunately, the board has to be lifted to see the traces and board designation, but that is easy to do. Good find, -Mike |
Tue, 03/25/2014 - 09:55
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