[BUILD] The Rude Tube IVORY ====== Official build & support thread

[gaetan]

Hi Bern

I am going to do a unit with most of the mods mentioned in this thread like Pot on R15 with a 1ma meter, in out vu meters, in out trafos, etc etc.

I am going to add a few extra frequencies to the tone stack high and low by routing  C3 and C6 to a switch with a few different cap values , from the tone stack calculator it seems the mid frequency is better left alone.

I plan to add a bypass to the tonestack section but i struggle to figure out if i need to compensate for the loss in the tonestack.
Is there a big difference or hard bypass would work?
I will probably figure it out but i thought you might have tried it yourself and could maybe share some knowledge.

Thanks in advance

 

[bernbrue]

Hi,
You can mod the rude tube Ivory as you like. It's a nice platform for experiments. I've built my unit completely stock. There is a noticeable gain loss by the tone stack, depending on the setting especially in the mid frequency.  Pay attention, the overall gain of the ivory is not very excessive, you might use higher ratio input transformer (1:4) to compensate.
Bernd

 

[gaetan]

Thanks for the info

In was going to use some 5402 for in and out
but since you mention the gain loss i'll try some 600/15k Edcor 1:5 ratio for input and i 'll stick to the 5402 for output

 

[bernbrue]

Good idea.
Bernd

 

[gaetan]

Hi Bern,

the Rude Tube on the bench, it sounds quite amazing.

i have tried a 5k pot on R15 and it works better for me. it adds some extra range.

but the unit is actually very noisy with 6N2PEV, i still haven't wired the 1:5 trafo which should help the signal to noise difference.

is the 12ax7 less noisy?

 

[bernbrue]

Hi,
Normally the Russian tubes are very good and shouldn't cause any noise. Check your grounding, especially the heater to ground connection on the psu.
Bernd

 

[gaetan]

Hi,
Normally the Russian tubes are very good and shouldn't cause any noise. Check your grounding, especially the heater to ground connection on the psu.
Bernd

thanks for pointing it out, 50Hz buzz, it seems fiddling with the grounding on the Power supply helps and grounding the tube helps a little. I'll tackle it when it's racked.

For those interested in making the toneshack interesting i wired switches with caps of the following values
Highs, C3: 220p, 100p, 47p, 33p
Mids/bass, C6: 0, 22n, 47n, 68n

The bass is more affected by changing C6 which is the mids cap and i found that changing C4 doesn't do much and is best left alone.

 

[dmp]

Just been trying mine out and it's sounding great. With a telecaster, pbass, moog synth, and rhodes, only the Rhodes was still lacking without a  full amp and speaker. The others were great direct in.
I switched the input pot to 1M, and clipped out the 1M pull down resistor. With both of these in parallel, the input impedance is lower and the tone suffers from a passive pickup. I also wasn't interested in the low impedance setting so omitted that.
A few notes:
For grounding, the center location on the psu should have a jumper connecting the two ground planes, and then a wire going off here to ground to the case. The case should also connect to the power ground.
I ordered the 6v transformer but ran it to the psu to get the heaters DC. This isn't a problem because with this type of rectifier - you get plenty of voltage to run into the regulator. Don't think a 9v is needed- and in fact the 6v reduces the heat dissipation significantly.

 

[bernbrue]

Very nice and tidy built. Congratulations. Enjoy it!
Bernd

 

[dmp]

I'd like to use transformers for a balanced in/out so I can use this with line level signals.
I've tried the output into a couple different direct boxes - a Jensen DB passive (12:1) and a bo Hansen active DI.
I liked the active a little more, but the passive step down transformer did work.
I'm not sure what to do on the input.
I tried this with a reamp which steps down the line signal to instrument level and it worked, with level loss. But I also thought perhaps it should have a 1:1 line level transformer, or even a step up 1:10 transformer if it would be seeing mic levels.
Has anyone already figured out the best transformers to use?

 

[museic]

I've got most of the power supply stuffed. Just a couple questions...

I got the ic3 listed in the bom. Mouser part # 595-LM317LCLPRE3 .But it's a different body type than the ic2 style. Does this not need a heat sink?

For r8 and v+rled am I choosing which resistor based on which power transformer I have?  My transformer is 2x6v secondaries. So wiring in series for 12v. So I would choose 2k resistor for r8 and 2.4k for v+rled?

 

[bernbrue]

Hi,
IC 3 should have the same body type as IC1 and IC2. When used for relays and lights only, IC3 doesn't really need a heatsink.  Resistor values are correct.
Bernd

 

[gaetan]

Hi,

I ve tried pretty much everything possible to give it more low end bellow 80Hz, Is the high pass effect  is due to the nature of the tube or am i missing something? I m using russian tubes, Are the 12AX7 more bassy?

other than that it sounds pretty good.

 

[bernbrue]

Hi,
Play around with various EQ settings and you will realize that the different bands (low, mid, high)  influence each other. An almost flat EQ can be achieved by setting high to 12 o'clock, mid to maximum and low to 2 o'clock. It's a Fender tonestack, not a parametric EQ.  Do you use any transformer for in or out?
Cheers
Bernd

 

[gaetan]

Hi,
Play around with various EQ settings and you will realize that the different bands (low, mid, high)  influence each other. An almost flat EQ can be achieved by setting high to 12 o'clock, mid to maximum and low to 2 o'clock. It's a Fender tonestack, not a parametric EQ.  Do you use any transformer for in or out?
Cheers
Bernd

I have modified the tone stack to death and i am pretty sure it doesn't come from there and i have kept one setting that is the original tone stack circuit.
i have some Edcor 600/15 on the input and some 5402 on the output.  and since you mentioned it it might actually come from the 5402.

 

[bernbrue]

Ok, measure frequency response without input transformer. In case you have no drop below 80 Hz you
should take out C1m and bridge the contacts.
Do the same without output transformer. In case your low frequency drop has gone, you should try to increase the value of C8m.
Cheers
Bernd

 

[gaetan]

Ok, measure frequency response without input transformer. In case you have no drop below 80 Hz you
should take out C1m and bridge the contacts.
Do the same without output transformer. In case your low frequency drop has gone, you should try to increase the value of C8m.
Cheers
Bernd

Thanks Bern, it's the 5402 the problem, i actually checked the wiring to be sure and it just doesn't sound right with the 5402. it actually distort quite a lot and the overall low end is definitely lower.

Any suggestion for another output trafo that works. i might as well just replace them without changing the circuit.

 

[bernbrue]

How did you wire the 5402? 4:1? Pin 3 to ground?
Bernd

 

[gaetan]

How did you wire the 5402? 4:1? Pin 3 to ground?
Bernd

4:2 i suppose, pin 3 to ground

 

[bernbrue]

Try connecting it as shown in the data sheet, bit leave out the resistor.
http://www.lundahl.se/wp-content/uploads/datasheets/5402.pdf
You might increase the value of c8m (~ 1uF).
Bernd