VVR versus Master Volume in 5E3 amp

[Mark]

Hi, I was wondering which is the better option in a 5E3 Deluxe?

The M.V. is far simpler to install and possibly more reliable, but there is no distortion via the output stage.

VVR reduces the available voltage and thus the headroom of an amp and possibly the distortion is more “natural” but does the timbre of the amp change with voltage and how much effective range does VVR compared to a MV?

Thanks for your assistance.

[DimenBrun]

I’ve done this with a circuit similar to a 2204 marshall, but using cathode biased 6v6’s. VVR works down to a certain point (still somewhat loud though) and then lower than that you lose the power tube distortion quality. I can’t get bedroom volume convincing tone, for sure.

The VVR implementation I used lowers the voltage of both power amp and pre. You might do better only lowering power amp, but I haven’t tried that.

[Mark]

Thanks for taking the time to share your findings with me. I appreciate that.

[Yoda]

I added a MV to my 5E3 to make use of the silly ‘Standby’ switch hole and it’s just ok. Gives you a light crunch at low volume option but it’s just not as good as pushing the whole amp through an attenuator.

[Mark]

Thanks for your advice, I appreciate you taking time to assist me.

[psb962]

It seems that a lot of 5e3 clone owners end up with an amp that is stiffer, louder, and won't distort at low enough levels compared to a vintage 5e3. As modern power transformers have lower internal resistance, and utility AC is higher than in the past, its common to find that the B+ voltage in the amp is above the norm of 370. Mine is 390, with either a JJ or a RCA 5y3 rectifier.

I looked at master volume and decided against that as all it does is allow more preamp distortion.

I did also research VVR and while that is a better solution, I didn't see variability as important.

The 'more at lower volume' thing I did on my build was use a '5e3 Speed Shop A12Q' speaker as it's low efficiency as well as sounding great. Also, yesterday I swapped out the CTS volume pots (which fall off a cliff at 2.5) for Alpha pots, which go all the way down to 1 and make it easier to play at low volume.

Finally, to get more sag and drive at higher volumes I'm going down the rabbit hole of reducing B+. Having read a lot of threads here, it seems the options for that are:

1) Sag resistor of about 100 ohm between rectifier and first filter cap to put back some of the resistance that is missing from a modern vs vintage power supply; this should deliver some sag and about 8V B+ reduction.
2) Zener or MOSFET B+ reducer on the center tap to ground connection to take off another 10-20V of B+ if (1) isn't enough (is it ever?)

[Aaron]

Sometimes if I want lower volume I use an inefficient speaker. Everyone these days wants loud amps with loud speakers. Try using an older/used speaker, I’ll like the older Celestions, Rocket 50’s or the L magnets.

[pdf64]

The red to red resistance on a couple of different posh (mercury magnetics & soursound) tweed deluxe mains transformers is around 350-450 ohms.

The OT their red to blue resistance is very high, 600-800 ohms.

A correspondent who's chasing the perfect tweed deluxe took the above readings at my request.

The Soursound guy seems like he's investigated the originals fairly extensively https://soursound.com/products/tweed-de ... former-set

[Mark]

The red to red resistance on a couple of different posh (mercury magnetics & soursound) tweed deluxe mains transformers is around 350-450 ohms.

The OT their red to blue resistance is very high, 600-800 ohms.

A correspondent who's chasing the perfect tweed deluxe took the above readings at my request.

The Soursound guy seems like he's investigated the originals fairly extensively https://soursound.com/products/tweed-de ... former-set

I have looked at Soursound and they are expensive, the tweed deluxe set is $475usd versus Mojotone at $220usd.

Edit: Mercury Magnetics comes in at $309usd.

[pdf64]

Yes, sorry, I don't think you're looking to build an exact replica, so the info I posted wasn't particularly relevant to your original query, it was more of an offshoot / diversion.

[Mark]

Yes, sorry, I don't think you're looking to build an exact replica, so the info I posted wasn't particularly relevant to your original query, it was more of an offshoot / diversion.

That’s fine, I’m not familiar enough with Tweed Deluxe 5E3 amps to know the difference between a good vintage amp and a modern reproduction. Thus my concern at paying for something that I’m unaware of the benefits of. If I bought Soursound transformers I don’t know what I’m paying more money for.

[ChopSauce]

I tend to believe that the VVR is best if you intend to play mostly at low volume levels. At least, mine is working fine in this case, but I couldn't get rid of some extra noise when cranked. Out the top of my head, I could read some post(*) which suggests that the grounding scheme is rather picky with a VVR. Still haven't investigated the issue, though.
_
(*) I'm sorry I can't find it anymore