Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Canezila on April 30, 2024, 10:15:35 am

Title: Robrob slo ef80 amp build question
Post by: Canezila on April 30, 2024, 10:15:35 am
Hi.  I have been building my first tube amp.  The robrobinette.com ef80 slo micro.  I have a question regarding v5. Would pin 4 (and pin 5) be heater pins?  I didn't see pin 5 labeled as used but in all other of the micro ef80 builds it is.  Can I get confirmation on this? Thank you.
Title: Re: Robrob slo ef80 amp build question
Post by: acheld on April 30, 2024, 10:34:07 am
Assuming you're using EF80's, then yes pins 4 and 5 are the heater pins. 

If you peruse the schematic, looking at the power section at the bottom, you can see how they are connected.

Title: Re: Robrob slo ef80 amp build question
Post by: Canezila on April 30, 2024, 03:23:34 pm
Thanks for the response.  I figured as much.  If you look at what I am attaching, it doesn't show it being attached.  I didn't know if it was intentionally missing.
Title: Re: Robrob slo ef80 amp build question
Post by: mresistor on April 30, 2024, 04:11:16 pm
Its also helpful to look at tube data for an EF80   
Title: Re: Robrob slo ef80 amp build question
Post by: sluckey on April 30, 2024, 04:15:37 pm
When you crank out as many nice layouts as Rob has, you're bound to make a tiny error. I know I do.
Title: Re: Robrob slo ef80 amp build question
Post by: Canezila on April 30, 2024, 06:39:27 pm
Its also helpful to look at tube data for an EF80

I am not complaining or anything like that.  I am very grateful for all the information that Rob Robbinette has provided.  I looked at that diagram and it helped me to realize I need to look into this further. So I asked that question because I am, in fact, very new to building tube amps.

This is my first build.  I know nothing.  I am wanting to learn and build an amp I love.  All I am doing is trying to figure out why my build is not working.  Probably because I so new to this that my build is garbage.  I am going to rewire my ht because it looks bad.  I bought better wire and better tube sockets.

I am enjoying this process.  It is going to take a few builds under my belt to get a solid grasp on things.

Everyone, please understand, (and it's hard to get the gist when reading black and white text), that I am completely grateful for any help and all the amazing work and knowledge that Rob Robbinette has provided.  It's amazing.  I hope I am explaining myself better.