Question for joe

[Skynyrd77]

I have a question about this modwright pre I got. It has a tubed input with a ss output. And it had been sent back and modded with a tubed rectifer . What does this all equate to lol. I understand the in and out but what is the benefit and what does the rectifier even do???

 

[NavLinear]

I'm glad you didn't get a tubed rectum-fier. I'd be worried if you did.

A rectifier converts alternating current (AC) to direct current (DC) called rectification. In the Phase Linear amplifiers the rectifier consists of four semi-conductor diodes but in your case (ModWright preamplifier) the diodes would be vacuum tube.

 

[Skynyrd77]

I'm glad you didn't get a tubed rectum-fier. I'd be worried if you did.

A rectifier converts alternating current (AC) to direct current (DC) called rectification. In the Phase Linear amplifiers the rectifier consists of four semi-conductor diodes but in your case (ModWright preamplifier) the diodes would be vacuum tube.

Tomm is the ass reaming surgery and there better not be any tubed rectum nothing ...
but that being said lol when this modwright first came out it just had the 2 5687 input tubes and the rest was solid state. Well the original owner sent it back in for more upgrades and they added a upgraded power supply and the tubed rectifer !!! So my question is what is the logic/what do u gain or do by using a tubed rectifer??? What would make it a upgrade of normal??? Just trying to figure the reasoning out. It use a 5ar7 and 2 5687 on the input but has solid state output...
thanks nav..

 

[gadget73]

Honestly you don't get a lot out of a tube rectifier vs solid state. It does bring plate voltage up slower, but thats really about it. You won't get any switching noise like you get out of solid state diodes but that can be easily eliminated with small capacitors across an SS diode. If you've ever had the hood up on your PL, you'll probably see those caps across the bridge rectifier for just that purpose.

I expect if you google it, you'll get stuff about voltage sag and all that. Thats more related to power amps, and specifically guitar amps. In a preamp, the load is constant (class A) so you should not have any sag problems. Thats not a desirable thing anyway, it adds distortion.

Which rectifier is it anyway?

 

[Skynyrd77]

I sent it in to modwright for a check up. They have it now. But they just got it yesterday so haven't looked at it yet.in the pic in the back left you can see it. I'm not up on my stuff to know what it is for.

 

[gadget73]

Is that an octal base rectifier? If it is, I'll guess 5Y3GT or a 5AR4. Both are grossly overkill for a pair of tubes in a preamp.

 

[Skynyrd77]

Is that an octal base rectifier? If it is, I'll guess 5Y3GT or a 5AR4. Both are grossly overkill for a pair of tubes in a preamp.

Its a 5ar4. What do you mean when you say it's overkill. Any way of explaining to a dumb ass??? Lol it's hard to wrap my head around this stuff..

 

[gadget73]

A 5AR4 is rated to deliver 825 ma steady-state current. I'd be surprised if both tubes combined in that preamp needed more than 60 ma. its like using an 18 wheeler battery to start your lawnmower. It might do it, and it won't hurt anything but its just more than you really need for that job. On the other hand, the thing ought to last forever since its not being abused at all. Rectifiers are actually extremely reliable tubes when used within their limits.

 

[Skynyrd77]

A 5AR4 is rated to deliver 825 ma steady-state current. I'd be surprised if both tubes combined in that preamp needed more than 60 ma. its like using an 18 wheeler battery to start your lawnmower. It might do it, and it won't hurt anything but its just more than you really need for that job. On the other hand, the thing ought to last forever since its not being abused at all. Rectifiers are actually extremely reliable tubes when used within their limits.

Cool that puts it in a way I understand.. Thank you for taking all the typing time