I just got these three Fivre 6C5G dirt cheap at a local place and I'm pretty stoked. The two brown base ones look like what you would expect them to, but the black base one has me a little confused. Other than the different stamp, I have never seen the top section like this. I don't know what...

That's good to know. It's not really about leaving it on, rather than about those times when I just turn it on before making something to drink and get lost in my kitchen for some 20 minutes lol Still, that was an interesting thread. Thanks for sharing.

Yeah I was aware of output transformers needing a load, so I was wondering if there might be any other reason for a Crack to suffer with no output connected.

I saw a discussion come up, so I started wondering. Does leaving a Crack running with no headphones connected for prolonged amounts of time damage the amp? I'm used to leaving my headphones connected even while warming up, but never really made sure if it's the correct thing to do.

Thank you! I've been experimenting. I was also lent a pair of nos GEC L63 which I was eager to try, but unfortunately one of them is really noisy, so I'll have to wait for another pair eventually:triportsad: They're Mullard 6J5G's in an adapter made by Deyan. They're very pretty tubes. The...

I appreciate the concern. I have actually solved the issue some weeks ago (one of the resistances in the right channel path was causing the issue). I have been enjoying my amp every day since then :)

While looking at the speedball manual I noticed a difference between the layout of the ground wires for the center lug of the 9 pin socket: while in the stock Crack manual the ground wires do "center tube lug -> potentiometer ground lug -> terminal 3", the speedball has a wire going from the...

The first connector is exactly what I had in mind. Thanks, I'm off to finding one in the EU now. Your kit looks gorgeous by the way!

I'm happily listening to some recently obtained 5998's and a pair of new output caps as we speak. I'm thinking I will just go ahead and try the speedball too, and finally see for myself how it is :o2smile:

That's good to hear, honestly. I very much enjoy my Crack, but I have an assembled speedball pcb sitting on my desk ready to be soldered on, and I can feel the effects of upgraditis hitting.

I had actually thought about just saying "whatever, let's try to solder the speedball on and see if that fixes it" but stopped since it didn't sound like the brightest idea lol. Either way, I have yet to decide if I want to install the speedball, since I've heard mixed opinions about the changes...

The issue had to be most likely on the right channel, since it was the only one affected. Replacing the volume potentiometer, output caps and sockets didn't change anything, so it had to be something in between. Turns out it was that resistor.

On another note, since during this time I was also suggested to make sure to keep the headphones unplugged while turning on and off the amp, I got to thinking about something else. I don't dig the idea of inserting and extracting the headphone jack at least twice a day (and I do like to switch...

Just giving some brief positive news to close the topic: I finally managed to find the fault. It was actually the 22k ohm resistance in the right channel, that for some reason was being noisy. Replacing it completely got rid of the issue. I don't know why the issue wasn't appearing back at the...

I want to buy one so I would like to receive photos, if that is what you mean.