Hoffman Deluxe Reverb build: rectifier not lighting

[Joeriz]

Hi all,

I just completed a Hoffman Deluxe Reverb build. The amp powers up OK but the rectifier tube is not lighting up and, as a result, there is no B+ voltage. I'm measuring about 670vac on pins 4 and 6 and about 5.5vac on pins 2 and 8 which all seems normal. I've also pulled the rectifier and plugged it into a known good amp and it works fine.

What am I missing??

Thanks,
Joe

[DummyLoad]

miswired or bad socket.



--pete

[sluckey]

Do you have 5VAC ***BETWEEN*** pins 2 and 8?

[Bangy]

PINS - You could try continuity check on both sides of the same pin. If you used an old socket it could need some love. I like to lightly moisten a rag with spray solvent to dampen the tube pins, then push in and out the tube a few times.  And check that the tube is making good contact. . . Regardless, You may need a small pointy object to make sure the tube itself is making contact in the holes.

I've found Filaments dont like big globby solder. And solder joint that looks suspect, heat it up, remove excess and try again.

[Joeriz]

Do you have 5VAC ***BETWEEN*** pins 2 and 8?

Yes, 5vac between pins 2 and 8.

The wiring looks fine to me so far...nothing obvious. I'll take a look at the socket itself when I get home tonight.

[DummyLoad]

close-in pictures would help too. 


--pete

[Joeriz]

I can post better pics when I get home if need be.

[Joeriz]

Close up...

[pompeiisneaks]

It all looks right from my perspective, as noted maybe a bad socket, or maybe, accidentally you put the socket in 180Deg from what you thought so you have it wired in reverse and have the 5v on the HT and the HT on the 5v pins? 

[sluckey]

so you have it wired in reverse

I agree. If I'm seeing the key correctly then the red wires are on pins 1 and 7 and the yellow wires are on pins 3 and 5. Luckily that miswiring does not cause any explosions. See the pic...

[Joeriz]

Sorry, the resolution on the last pic wasn't good enough to be able to see the key. Here's a better pic; looks like it's installed correctly. I'll do some more testing.

[sluckey]

Sorry, the resolution on the last pic wasn't good enough to be able to see the key. Here's a better pic; looks like it's installed correctly. I'll do some more testing.

Socket is wired wrong. You need to move every wire one pin counterclockwise.

[DummyLoad]

Sorry, the resolution on the last pic wasn't good enough to be able to see the key. Here's a better pic; looks like it's installed correctly. I'll do some more testing.

Socket is wired wrong. You need to move every wire one pin counterclockwise.

yup, ya kinda' knew it had to be, right? new build and all + fairly rare occurrence that a socket is bad.


--pete

[Joeriz]

Sorry, the resolution on the last pic wasn't good enough to be able to see the key. Here's a better pic; looks like it's installed correctly. I'll do some more testing.

Socket is wired wrong. You need to move every wire one pin counterclockwise.

yup, ya kinda' knew it had to be, right? new build and all + fairly rare occurrence that a socket is bad.

--pete

Doh!  Yes, I figured it had to be me. Anytime you stare at something long enough you're bound to overlook something. Thanks all for the help!

[sluckey]

The pin numbers on that socket are confusing and kinda useless. I've seen other sockets that are even worse. Best to just ignore the numbers completely and just follow the key notch. The notch will ALWAYS be located between the first pin and the last pin. For octals, that means between pin 1 and pin 8. Viewing from the bottom, pin 1 will be the first pin clockwise from the key. Then just count up in a clockwise direction. ***CAUTION*** Don't think in terms of left or right of the key. Think only in terms of clockwise as viewed from the bottom.

Before you power up you may want to verify those other two octal sockets are wired correctly.

[Joeriz]

The pin numbers on that socket are confusing and kinda useless. I've seen other sockets that are even worse. Best to just ignore the numbers completely and just follow the key notch. The notch will ALWAYS be located between the first pin and the last pin. For octals, that means between pin 1 and pin 8. Viewing from the bottom, pin 1 will be the first pin clockwise from the key. Then just count up in a clockwise direction. ***CAUTION*** Don't think in terms of left or right of the key. Think only in terms of clockwise as viewed from the bottom.

I agree about the confusing numbering on the socket. I've used these before, knew they were confusing, double checked the orientation, and STILL messed it up! 

Before you power up you may want to verify those other two octal sockets are wired correctly.

Oh yes...absolutely!

[Ed_Chambley]

The pin numbers on that socket are confusing and kinda useless. I've seen other sockets that are even worse. Best to just ignore the numbers completely and just follow the key notch. The notch will ALWAYS be located between the first pin and the last pin. For octals, that means between pin 1 and pin 8. Viewing from the bottom, pin 1 will be the first pin clockwise from the key. Then just count up in a clockwise direction. ***CAUTION*** Don't think in terms of left or right of the key. Think only in terms of clockwise as viewed from the bottom.

Before you power up you may want to verify those other two octal sockets are wired correctly.

Are there numbers on octal sockets?  Who wooduh thunk it.

[Ed_Chambley]

Sorry, the resolution on the last pic wasn't good enough to be able to see the key. Here's a better pic; looks like it's installed correctly. I'll do some more testing.

Socket is wired wrong. You need to move every wire one pin counterclockwise.

yup, ya kinda' knew it had to be, right? new build and all + fairly rare occurrence that a socket is bad.

--pete

Doh!  Yes, I figured it had to be me. Anytime you stare at something long enough you're bound to overlook something. Thanks all for the help!

Yep, It is always me when an amp doesn't work right..............................except when gremlins are amongst.

[Bangy]

Great catch. Sluckey

Glad you got it all sorted out.

A helpful tip - I like to put a piece of blue painters tube on the chasiss next to pin 1 on any unfamiliar socket. Then when wiring is complete its gone and no one knows your dirty little secret.

You amp looks tip top BTW

[shooter]

no one knows your dirty little secret.

I use a black dot, IC chips have them, why can't I

[sluckey]

I'm pretty good at using the notch key or space key to count pins. Seems foolproof to me. Been working for over 50 years for me.

[Ed_Chambley]

I'm pretty good at using the notch key or space key to count pins. Seems foolproof to me. Been working for over 50 years for me.

Yep, the comment I made about not knowing octals had numbers I stole from you.  Now I have use it 2 times.  The rule is if you use a saying 3 times, it is yours.  One more time and I own the wise crack remark.

[purpletele]

Joeriz,

Nice work!

That looks fantastic

[Joeriz]

Joeriz,

Nice work!

That looks fantastic

Thanks! Hope to be playing it this weekend!