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Title: Just received kit, a couple of Q's Post by: marT on January 27, 2011, 09:30:39 PM Hi all,
I just received my TMB EF86 kit and I have a couple of questions. Is it advisable to use the diodes + cap on the rectifier tube? What does it do? The pictures don't show them on there so I am a little confused about it. Also, with the shielded wire to V0 is it best to attach the 68k resistors at the input socket end or have them split at a tag board attached to the tube socket? Also I am assuming these get wired to the "main wire" of the shielded cable and the ground (green in the layout) is the braided part? Thats it for now, I would apprectiate any help. I'm sure there will be other questions later but thats really the only things I have questions about at the moment. Thanks, Martin. Title: Re: Just received kit, a couple of Q's Post by: wyatt on January 27, 2011, 11:40:29 PM Nik strated adding the diodes and caps to prevent surges on the rectifiers when using standby switches, form another thread here...
As for the diodes on tube recto - The primary reason is really GZ34 with standby switches. If you want to watch some mini fireworks, try amp that uses GZ34, and also has standby switch. Toggle the standby switch on and off a few times and you most likely pop the GZ34. This happens to new or even NOS tubes. The diodes prevent surges from hurting the GZ34, aided by the cap. Actually, 5Y3, EZ81, 5U4 etc, dont have much of this issue like GZ34. But we just put it there cause, as you know, some will be itching to put GZ34s in 5E3, for example. It's a few extra solders, I would use them. You can do either with the 68K resistors. Title: Re: Just received kit, a couple of Q's Post by: marT on January 28, 2011, 07:45:22 AM Thanks for the info. Makes sense really.
I'll update this if I run into any more queries! Title: Re: Just received kit, a couple of Q's Post by: JohnA on January 29, 2011, 12:07:20 AM They are there to protect the rectifier from surges. Delicate things rectifiers, definitely use them, these parts have zero effect on what the amp sounds like they are just there to keep it working.
Title: Re: Just received kit, a couple of Q's Post by: marT on January 29, 2011, 01:38:46 AM Thanks, I put em in
Ok another possibly stupid question. I already hooked up al the heater wires and was just about to wire up the power switch/lamp etc. I realised that the lamp is 6v and should be connected to the heaters. What is the appropriate way to hook this up? Should I desolder the connections from the PT to pins 4/5 of V5 and solder them to each of the connections on the lamp and then from the lamp back to pins 4/5 of V5? Or should I just run wire from pins 4/5 of V5 back to the lamp connections? I guess the first way uses less wire and is therefore less messy? Also something else I noticed. I don't have an Earth tap coming off the power transformer. A black wire with a 0 printed is the last wire which I am guessing goes to the neutral on the mains socket. I don't have any wire after that to earth like it shows on the layout. The transformer is printed with 17 Jan 2011 so maybe this is a new design that earths itself? Title: Re: Just received kit, a couple of Q's Post by: arledgesc on February 22, 2011, 04:30:20 PM I wired the lamp to the transformer as that was the closest place to do so.
Contact Nik about the transformer Earth gnd. I believe my year old transformer had a wire or a connector lug for this. |