Bottlehead Crack + Beyerdynamic T1 2nd (600ohm) insufficient volume

[Varail]

Removing the pad will make it play louder. I your photo you can see a small tan resistor connected between the two outer terminals on the volume potentiometer (one end is where the white wire for the left channel is connected through a big tan resistor and the other end where the black wire for ground is connected). This resistor gets removed. There will be another small tan resistor just below it connected the same way to the potentiometer terminals closer to the chassis (right channel, red). Remove it too.

The next step is slightly more involved. There is a bigger tan resistor that connects the white wire the terminal on the potentiometer. That resistor needs to be snipped out. Then solder the loose white wire directly to the terminal where the big tan resistor was soldered. You now have the white wire connected directly to the pot terminal without the tan resistor in between them.

Once again there will be a similar larger tan resistor underneath that is connected to the red wire and to the lower terminal. Do that same thing here, remove the resistor and connect the red wire directly to the pot terminal.

All of this returns the input wiring to the stock kit configuration.

I would also advise that if you are hiring someone to do this rather than taking it on yourself, a competent technician should understand what an input pad is and know exactly what I am describing here. If he does not, find a tech with more knowledge.

There is nothing in electronics I would do by myself other than replacing batteries.

However the 1st thing that "I" need to do is switch it from 110V to 220V so I can get rid of the converter.
Would you be so kind to tell me what should be done (looking at the picture I provide).

Before removing the mod is there any measurement to be done to see if the BC delivers the expected power with the included mod. (other than listening).

I still hope kGlerup could tell us if he has the mod on and what would he get if he  would replicate my experiment (same track + Beyer). He said he has plenty of gain but he diddnt say if he has the mod installed or not ..

Tx

Update :

I used my LCD X on the BC and maxing everything they are slightly behind in volume compared to the Beyer 600ohm/Sen 150 ohm. Being a planar I was expecting a big difference but no ..

[kGlerup]

I still hope kGlerup could tell us if he has the mod on and what would he get if he  would replicate my experiment (same track + Beyer). He said he has plenty of gain but he diddnt say if he has the mod installed or not ..

Easy on the patience 
I'm sound asleep when you write 
No, I don't have the L-pad, only change on mine is an ALPS pot. As mentioned, 10 o'clock (30% roughly) is the highest I go and that is LOUD!
But it's never been a problem, maybe because the ALPS is very precise.
I prefer to have the gain "ready" in case I connect something else.

[Paul Birkeland]

You can also just clip out the pair of resistors that go between the outer lugs on each level of the pot to substantially reduce the amount of padding.

[Varail]

Dan (US) is the person I bought the amp from and he was kind enough to reply :
"Not even close to max volume. If you break the volume knob into ten increments the Beyers couldn’t go more than a 4. Tops. 5 would hurt. "
So basically the same thing that everyone else here is saying, I should have enough gain.
So he couldnt budge past middle while I still need more on max.
That means either Im that stupid Im doing something very wrong here or the unit got issues from the US-EU transit. I wont doubt either of them ..

Removing the resistors like Paul suggested is fine as long as the unit behaves normally which it might not be the case so I will sleep on it for now.

The next thing Im going to do is ask someone to switch it from 110V to 220V to remove the converter from the equation.

What should he do ?

Thank you

[Paul Birkeland]

I would get a handheld volt meter with a 2V AC range, play a 60Hz tone through your DAC with your system volume turned all the way up, then measure this voltage across each RCA plug coming from your DAC with the meter.  This would 100% verify that you have an issue with source voltage, and then you could feel confident that this is where adjustments need to be made.

Can you send a link to the step-down converter you're using?  It's also slightly possible that there's an issue there.

[Varail]

I used both the Ifi Nano and Qutest (set on 2v) so it is not the source.

This is a pic with the plate info of the converter.

[Paul Birkeland]

I used both the Ifi Nano and Qutest (set on 2v) so it is not the source.

Were both plugged into the same source?  I would continue to suggest the importance of measuring the output just so that can be checked off the list.

[Varail]

They are getting 2.07 V ( It was measured 2 hours ago ).

The BC is going to be converted to 220V . We will take it from there ..

[Paul Birkeland]

What tube is plugged into the 9 pin socket?  Did the seller include the stock 6080?

[Varail]

Western Electric 5998/421A
Yes he did.

[Paul Birkeland]

A 421A will not plug into the 9 pin socket.

[Varail]

I dont have the unit anymore. I gave it along with the tube but it was a big tube.
The 3rd one from the pic

[Paul Birkeland]

The 9 pin socket is the front socket, where the small tube goes.  There are certainly some pin compatible tubes that you could plug in there that wouldn't work properly, so it is worth double checking what's being run in there.