Can't attain a perfect OX Box "Speaker Volume" with my Deluxe Reverb. 3 is too quiet. 4 is too loud. What's the solution?

[markpaterson]

I have a 64 Custom Deluxe Reverb Hand Wired that I play at the edge of breakup on the Vibrato channel. It's a 20 watt amp.

The OX Box sounds great when the Speaker Volume is at 4, but it's just slightly too loud for apartment living. And at 3 I can definitely feel tonal sacrifices. I feel that 3.5 would be perfect, but sadly half steps are not possible.

I'm looking to shave off a few dB to get to a "3.5" volume level. Before you suggest it, I already plug into Input 2 on the amp, which is a few dB lower than input 1. I need to cut a little more though. I'm also not interested in just rolling down the volume pot on my guitar – I want to retain the full power and dynamics of the pickups and I prefer to control the volume using pick attack.

I want to list a few possible solutions that I'm considering, to get your opinions. Please feel free to suggest any more that you think of.

1. TUBE SWAP.
My current tube layout is this table below. I believe that I can swap possibly the V2 tube with one of a lesser value, but I'm not sure if that will mean a drop in dB or simply an earlier or later breakup? Looking for advice on this.

V1	12AX7	Preamp Normal Channel
V2	12AX7	Preamp Vibrato Channel
V3	12AT7	Reverb Send
V4	12AX7	1/2 Reverb Recovery 1/2 Gain Stage for Vibrator Channel
V5	12AX7	Vibrato
V6	12AT7	Phase Inverter

2. SPEAKER SWAP
The speaker is the stock Jensen C-12Q speaker. I understand that there might be a (Weber?) speaker that offers less output than this. I'm considering swapping this out anyway, for better tone. But would if this is also a way to reduce the volume a little then all the better.

3. PPIMV
Probably the most drastic solution, but I'm considering having a Post Phase Inverter Master Volume fitted. I have one installed on an old Super Reverb and it really does a nice job of taking off a few dB, ensuring that my Weber MASS attenuator isn't doing all the work. I don't detect any tonal problems from this approach.

 

[jaeger28]

if you can use two speaker outs on the Fender in parallel and the impedances match, then you could try using the Ox Box as a load on one output and run the speaker on the other output. That should give you half volume on the speaker with not much tonal impact of the reduction. This only works of course if a) the OX can be used as a load, not only as attenuator and b) the DLX has two parallel outs that match the impedance of the Ox and the speaker if used in parallel.

Of course if you aim for more than a -3dB reduction (half volume) this won't be a useful option.

 

[Ron76]

Hi!
The preamp tubes will not help, they rather affect the gain, not the volume of the amp.
The problem of the parallel connection (OX + speaker on separate outputs) of jaeger28 is that the speaker gets much less power when run through OX, because OX drags some of the energy from the amp to run its signal chain. I guess the amp will be even louder this way. But you can try.

PPIMV is a good solution I use on my Class A amps. But it requires circuit modification.

In Germany, we have a company called "Tube Amp Doctor" which produces / sells tube converters. With this, you basically can use the 6V6 sockets of the power tubes and run EL84 tubes in Class A configuration in them, which produce much less output (in your case, it should be 8W). They're often used and I've heard good things about them.
Here's a link: https://www.thomann.de/gb/tad_class...LCJjdXJyZW5jeSI6NCwibGFuZ3VhZ2UiOjJ9&reload=1
or: https://www.tubeampdoctor.com/tad-class-a-converter-made-in-germany?c=111
Best regards, Ron

 

[markpaterson]

Thanks for your help, both of you.

The Tube Amp Doctor convertor looks like an amazing solution. I had never heard of it. Unfortunately it's not something I can use, because I read in their small print that it will prevent any bias tremolo from working (the 64 Custom Deluxe Reverb Hand Wired is bias tremolo).

Regarding using two speaker outputs, that doesn't really solve the problem in my case because the in-room sound will still be loud from the speaker, even if slightly reduced. I'm looking for a solution that is entirely attenuator based.

I did end up trying 12AT7 tubes in the preamp sections. It affected the gain, as you said, but this does affect the perceived volume in the room, so in that sense it felt quieter. Maybe affected the headroom a little, but again it didn't seem like a problem. The only strange thing that happened, that I can't explain, is that when I put a 12AT7 in V2 but it actually affected the gain in Channel 1 (Normal Channel). I had to put the 12AT7 in V1 to have it affect Channel 2 (Vibrato). I ended up putting a 12AT7 in both. I expected a 12AT7 in V2 to affect Channel 2, etc but this was not the case.

I think I may just end up getting a PPIMV fitted at some point though, and go back to the 12AX7.