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Re: Build question 18 watt Superlite TMB
Posted: Wed 05/12/21 7:15 am
by JMPGuitars
katopan wrote: ↑Wed 05/12/21 6:43 am
JMPGuitars wrote: ↑Sun 05/09/21 7:28 am
Have you played a Superlite TMB? The preamp distortion is great. I've used a attenuator with it too, but even that wasn't really necessary.
Yeah. And I built a 2W submini version of the Superlite too, as well as the standard TMB preamp in one of my test chassis. Each to their own, although I am a self confessed overdriven power pentode addict. TMB preamp distortion is a flavour to blend into the essential power stage distortion for me. But I can certainly respect other options.
I hear that. Power tube distortion is the best, but in the Superlite TMB, I think the preamp distortion is also quite good. Of course the guitar and speaker effect the final outcome too.
Re: Build question 18 watt Superlite TMB
Posted: Wed 05/12/21 2:48 pm
by TriodeLuvr
JMPGuitars wrote: ↑Wed 05/12/21 7:15 am
I hear that. Power tube distortion is the best, but in the Superlite TMB, I think the preamp distortion is also quite good.
Preamp distortion in my 2104-based 36W is also excellent. Very smooth and lots of sustain. I attenuate the signal before the PI so only the preamp breaks up. It's a very familiar sound, reminds me a great deal of early Hendrix.
Jack
Re: Build question 18 watt Superlite TMB
Posted: Wed 05/12/21 9:12 pm
by zaphod_phil
katopan wrote: ↑Wed 05/12/21 6:43 am
JMPGuitars wrote: ↑Sun 05/09/21 7:28 am
Have you played a Superlite TMB? The preamp distortion is great. I've used a attenuator with it too, but even that wasn't really necessary.
Thanks Katopan, I intentionally designed that preamp to give good, thick distortion.
Re: Build question 18 watt Superlite TMB
Posted: Thu 05/20/21 1:29 pm
by mehfuzhoss
I have sourced most of the parts for this build. and getting excited to start the build. The PT is a hammond 290PAZ with 580VCT. What B+ voltage am I expecting please explain if possible. will I get 290-0-290 with this PT.
what does the 2.2K 5watt resistor do that connects the two 32uf of the can cap and how different value will affect the voltage on the plates of EL84? i forgot to order this resistor.
thanks
Re: Build question 18 watt Superlite TMB
Posted: Thu 05/20/21 2:14 pm
by JMPGuitars
mehfuzhoss wrote: ↑Thu 05/20/21 1:29 pm
I have sourced most of the parts for this build. and getting excited to start the build. The PT is a hammond 290PAZ with 580VCT. What B+ voltage am I expecting please explain if possible. will I get 290-0-290 with this PT.
what does the 2.2K 5watt resistor do that connects the two 32uf of the can cap and how different value will affect the voltage on the plates of EL84? i forgot to order this resistor.
thanks
580VCT (Volts Center-Tapped) is the same thing as 290-0-290. 290+290=580, and the 0 is the CT.
The 2.2K 5W resistor drops the voltage and isolates (along with the filter caps) the first and second B+ nodes. This resistor is essential, however, you can run any value between 1.5K to 2.2K as long as it's 5W. You will simply need to test your voltages and make sure the power tube screens are below the plate voltages. I recommend 1K 3W screen resistors.
Thanks,
Josh