Tube PSU Regulation

[nickt]

Maybe a dumb question but I've noticed a bunch of the old tube gear did NOT use regulated HV or even DC filaments (thinking of the V72 V76 here).
Has anyone had success NOT regulating HV or filaments for their tube preamps?

Thanks!

 

[zebra50]

Yup, no problem. Just follow an old schematic, get building etc.

And AC heaters can work fine if you're careful with your build. I did an Altec style preamp & vari-mu compressor with AC heaters and the hum is not noticeable in normal use.

 

[[silent:arts]]

My D-LA2A uses AC heaters (like the original) without any problems.

 

[nickt]

Kinda what I tought - certainly simplifies things a bunch.

My experience is with guitar amps so a totally different set of issues
AND no matter how good your amp is noise/humwise you plug in a strat and it all goes to hell - :shock: - still love my strat though... :sam:

Anyway worst case is I'll have to add a regulator later I guess.

Thanks guys

 

[okgb]

There are the Hum balence schemes for gtr amps
resisters or balence pot , you've worked those ?
but yeah the single coil p/u gotta rotate and find the null spot
[ and keep your hands on the strings often ]

 

[tk@halmi]

I have built preamps with LC + RC filter HV supply. LC filter adds some regulation and can be extermely low ripple. LC + RC filter will compete with an active element regulated supply. The drawback is that inductors are costly. If you have very low currents involved and RC + RC filter can be very effective at little cost.

As mentioned before look for hum balance pot arrangement for heater supply.

Tube circuits can be very simple and effective, but we tend to make them very complicated. I guess we each have an audiophile in us... :green:

 

[nickt]

[quote author="okgb"]There are the Hum balence schemes for gtr amps
resisters or balence pot , you've worked those ?
[/quote]
Yeah - added one to my AC30 - now it hums equally out of each speaker :green:

 

[PRNDL]

[quote author="nickt"]
My experience is with guitar amps so a totally different set of issues
AND no matter how good your amp is noise/humwise you plug in a strat and it all goes to hell - :shock: - still love my strat though... :sam:
[/quote]
Single coil guitar pickups can be noisy, but there are ways to reduce noise.
Proper guitar shielding usually helps with standard strats
http://www.guitarnuts.com/wiring/shielding/shield3.php

In a tube amp, lead dress and layout are critical, especially with high gain amps and those with pentode preamp tubes (EF86). Grounding is very important in tube amps.

The solution, as always, is to use your noggin to figure out what's wrong and fix it.

 

[nickt]

[quote author="PRNDL"]Single coil guitar pickups can be noisy, but there are ways to reduce noise.
Proper guitar shielding usually helps with standard strats
http://www.guitarnuts.com/wiring/shielding/shield3.php
[/quote]
I've seen this dude's stuff before. Some is relevant some is just rubbish (eg his talk about eliminating ground loops in your guitar oh p-l-ease! :roll: ).

Playing live with a noisy amp and a noisy guitar is not a problem. Things come to a head when recording.

My strat is 42 years old and I've been playing it for 35 years. It's in need of a bit of TLC at this stage (just like me! :razz: ).
So a bit of a service (and backout of all the "dumbstuff" done in the 70's) is on the TODO list :grin:
Probably should put together a "partscaster" with a set of Kinmans...
My AC30 is also 42 years old and all the above applys to it as well.

Over the years I've built a number of amps. Most recently a Lightning clone - it's dead quiet but no match for the noisy old Vox tonewise :sad:
Trainwreck and D'lite builds are lined up - so many projects so little time (sigh...)