50 watt lead or JTM45
Moderators: pompeiisneaks, Colossal
Re: 50 watt lead or JTM45
The 784-139 OT can be mismatched to put a 6k8 load on the power tubes, which seems to work fine for KT66 or EL34.
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Re: 50 watt lead or JTM45
I had a JCM800 2203 that came with 6550 tubes and it was the bomb but too loud. The 784-139 OT can handle EL34, 6550, KT66 and KT88 tubes.
I'm trying to find schematics and a layout for a 67' 1986 Bass JMP.
I want the tube rectifier vs SS and add a master volume to the rear so I don't go deaf or have to use an attenuator.
I'm trying to find schematics and a layout for a 67' 1986 Bass JMP.
I want the tube rectifier vs SS and add a master volume to the rear so I don't go deaf or have to use an attenuator.
Re: 50 watt lead or JTM45
The issue as I see it is that 3k4 is a heavy load for the 25 watt tubes, unless the cranked VB+ is under ~400V.The 784-139 OT can handle EL34, 6550, KT66 and KT88 tubes
Try plugging the numbers into http://bmamps.com/Tech_tds.html
Bear in mind to use the appropriate full load supply voltages, rather than static values.
https://www.justgiving.com/page/5-in-5-for-charlie This is my step son and his family. He is running 5 marathons in 5 days to support the research into STXBP1, the genetic condition my grandson Charlie has. Please consider supporting him!