How to repair fix Vintage Fender Vibroverb tube guitar amp noise + sockets D-Lab

Here's another great tube amp tip. Tube sockets can be a major trouble maker. A bad grid connection can melt down your expensive tubes. Always use top quality tube sockets, unless your just building a junk box special for fun. This Fender is an all time classic, highly sought after. Now it has Amphenol silver contact sockets. Very worthy of this amplifier. Hope you like. TD

[@jimtalltheislandbrothers6639]

Terry I second the comment below. Your videos are very informative and you are helping keeping an old trade alive. I have learnt so much watching your videos. Thanks a million from across the seas.

[@MichaelLloyd]

I like your troubleshooting techniques. Very methodical and documented well for us :)

[@DennisMurphey]

the more i watch the more I appreciate everything you do. Reminds me so much of the 70s Medical Systems R&D with PMT absorbing energy for CT Scanners and all the methods our EEs went thru to ensure a good clean signal for accurate x ray absorption data. You make me want a old Tube Amp so I can Hot Rod it the way you do. But at 68 i can't get all the gear you have to set up a shop. I am sure you must be encouraging young engineers to study and learn the techniques you have brought to the You Tube channel. Where can I get a Kit or parts neccessary to upgrade an old amp? You could publish a Fender Amp workbook with tips, tricks, parts lists, sources, resources and schematics, folks would pay such a book

[@djfrank59]

When it comes to a grid biased amplifier, I've been doing exactly what you did here...installing 1 ohm resistors to ground and measure the drop across the resistors. Some use the output transformer shunt method (which is a lot more dangerous) or some techs even disconnect the OT's center tap, place the meter in between and measure the current and divide by the amount of tubes in the output stage. But I've found that the 1 ohm resistor trick works. Great video! Keep 'em coming :)

[@CountryHitsUSA]

Now that's Truly a Professional Job!

[@brianwalker6849]

Hi, I always take a photo on my i pad of all wiring jobs before I get started it works for me!!.

[@fmercer54]

I enjoyed a day with fender and the marshally bit awsome, and the tech stuff even more awsome. Thanks Terry.

[@daveogarf]

"Snozzley", the giant stepper bit - NICE! Great job, Snozzley!

[@LarryDeSilva64]

I have a box of those porcelain sockets I picked up when I bought a box of parts at my Ham and HiFi store. As you can guess I almost gagged seeing them packed in their orginal boxes. I have that same Beckman Meter you are using on my work bench as well. Thanks for sharing Terry.

[@mattdixon333]

Hey Terry! loving these videos. I've chain watched dozens. Keep up the great work - greeting from sunny Melbourne, Australia!

[@coenfilm]

Really interesting. Beyond my skill level but I enjoyed it. That’s why I take my 67 Deluxe Reverb to professionals.

[@MrCnema]

Oh, I love these shows...lot to learn from.. thanks from the Netherlands !

[@jwl9286]

Great Video! The way every step is detailed is wonderful. Love watching the current through the tube too. Thanks

[@DragonCrestPC]

Awesome as always, great job!

[@matthewf1979]

Oh the priorities! $500 in Snake Oil transformers and $20 worth of China parts inside the chassis. Then the owner has to take it to you to replace parts that should have been installed (at least Belton sockets) in the first place. It's mighty kind of you to install those amphenol sockets, they're getting really pricey!

[@theweniscoqui]

Love your vids. keep up the good work

[@idogepgyar]

Thanks Terry, great videos as usual, and "always look for the obvious"!

[@meblaw1]

enjoy all your amp repairs! can you show how to make a "dummy load" resistor for the speaker jack and how to drain the filter caps with a resistor, how many ohms and watts for each?

[@stratslinger4492]

Matt Fields, that is my amplifier Terry fixed. You're right, it was nice of him to replace the tube sockets. But I resent you're comments about snake oil transformers (they're Mercury Magnetics) and cheap China parts. That amp is is 12 years old and has performed like a champ every time I've ever used it. Gigged with it at least 50 times, no problems. This is the first repair I've ever needed for this amp in that time, including the tubes. I can't afford a real Vibroverb but this clone has given me the opportunity to get close. Its easy to take shots from the cheap seats, isn't it?

[@audiotechlabs4650]

Stratslinger I saw the workmanship on that amp, it looked better than a 65' BF. I build and repair with Classictone iron and have great sounding amps! They are not as expensive as Mercury Magnetics. I have had tube sockets loose their grip many times, no matter who made em'. I saw the JBL speaker, so this amp is no slouch! Thankz

[@d-labelectronics]

I agree man, The builder was top notch. No complaints. The socket issue was the only thing needing improvement.

[@davidsigglekow1349]

Rectum-fier tube Lol Great work sir

[@bobcorbin7545]

Good one, Terry. Thanks.

[@wadehicks9270]

Great job Sir.

[@sski]

LMAO! "Rectumfier"! Dude! Your channel rocks! Thanks!

[@bmcash3411]

This is great. Thanks!!

[@DeadKoby]

The Sovtek 12AX7 LPS is a good one... Try the TungSol 12AX7 also... Those are a personal favorite of all in current production.

[@dhpbear2]

1:00 - Someday I want to put together an amp where the tubes are hard-wired and the electrolytic caps are socketed :)

[@nikkihendrix1234]

I do the same thing with wires in terminals/ sockets, makes it nice and snug and makes soldering easier. you shouldn't have to hold a joint while you're soldering it.

[@JRP3music]

My amp is having an issue with V1. The Clean channel lost gain. The preamp tube was difficult to put in. My ch. 3 was causing random feedback. Volume control on the guitar would not stop feedback unless I switched to ch.1 clean. I carefully removed the tubes to label them. That was when so discovered the V1 issue. I replaced V3& V4 to see if microphonic issue went away. Then the clean channel dropped in gain.

[@russphilly]

thank you...well done.

[@ferraridinoman]

Great video! (Nice JBL speaker!)

[@Tonetwisters]

I wanted to hear the amp cranked up ... but ... guess the cat was sleeping and didn't want to be disturbed by Daddy's guitar noise ...

[@JEmilioJNava]

I dig and and love the "lab" approach, congratulations man ... I always wonder if Leo thought about what he did as a Lab? a playroom? a man's cave? ...

[@Tonetwisters]

... A paycheck.

[@jamiee172]

Pretty cool!

[@RobertKohut]

Nice, thanks!

[@randallissimo]

Why would you replace new sockets if you don't have any hard evidence they are bad?

[@Stratbass]

Thanks!

[@bernhardnizynski4403]

With regard to the noisy preamp tubes - could the sockets have also been dirty thus creating noise - when you replaced the new tubes, maybe the extraction/replacement process cleaned the sockets?

[@mojogearfx]

Great video again!Do you leave the 1 ohm current shunt resistor hooked after you finished with the repair( bias) ? Thank you very much!

[@pneumatic00]

I'll answer for Terry. Yes, you leave them in, for future bias checks or in case the amp needs a repair. The output tubes do not even know that 1 ohm is there.

[@dennisqwertyuiop]

I have all sizes greenlee punches up to 3 in and klien steep bits never thought to use stepper bits,, what size is the new hole need to be thanks good repairs you do

[@d-labelectronics]

This required 1-1/16" hole

[@kevinlbrockway]

Do you use a signal generator in your troubleshooting and if so, what would you recommend?

[@user-dn5ok5fz1t]

This is a JBL equipped amplifier.That's got the really nice metal dust capped speaker... I've heard those JBL equipped.Amplifiers sound absolutely wonder fu... That power transformer has been changed before hasn't it.... It has. The cheap p v c coated wiring on it instead of the cloth covered wire.

[@philipdonovan6510]

Old new stock Amphenols, damn, you're killing me here, thats great. What do you think of the new production Beltons? The remainder of the parts for a single channel '64 Vibroverb are coming in today and the tube sockets I ordered for 6L6 and 12ax7 are the brown micalex Beltons. Many people seemed to sing praises for them so, went with them. Hope they are not loose gooses like the ones in that Vibroverb!

[@joramkalfa4038]

Hey Mr D Where do you get those fancy sockets? Awesome video!

[@daveogarf]

SERIOUS UPVOTES for the long-neglected RECTUMfier tube! 8^D Also for SNOZZLEY, the Mega-step drill bit! He's a true hole hog!

[@johnbeutel-vb2fd]

Where is the best place to buy capacitors?

[@Haassan1]

Dear D-Lab,Do you perhaps have any books about repairing/building tube amps? Or could you recommend any?I am beginner, but phyics used to be one of my favored classes, so im familiar with most of the terminologie.

[@rciancia]

Terry, is that really a bias adjust or a balance adjust of the 2 output tubes. On my bassman 50's the pot is a balance and not a bias. Is this the same as the Deluxe ? Great video, thanks Terry

[@d-labelectronics]

Yes, this one is the bias set. I have seen that balance system you are referencing.

[@garyeggleton1142]

nice

[@Toology83]

I have the same amp and I am experiencing the same noise issue. I bet I have a microphonic preamp tube

[@Tonetwisters]

I'd be happy to have those tube sockets in every amp I have!! Shouldn't you move those resistors to the side of those new power tube sockets, not across the middle?

[@user-dn5ok5fz1t]

Hey, do you have this is the first time?I've gotten one of your videos sent to my account in a long time.I used to get your videos a lot.I guess maybe you've slacked off making them as of late..

[@sting1111]

Would you like to do a video on a noisy Marshall 1980 JMP 2203 that has been converted to point to point? I am in Ohio. Money talks.

[@DeDeNoM]

So, did you fix the eyelet? Or did it slip through a second time

[@d-labelectronics]

Yes, it was fixed

[@dhpbear2]

What's a 'clone' Fender? Is it counterfeit?

[@robertgraf9265]

Yes. There used to be a seller on eBay who sold chassis, faceplates, fiberboard, etc., for several different amps. There are also some US based sellers. You can find Fender, Marshall and Vox repros pretty easily.

[@dab745]

Why Mullard “too bad”?

[@jackleg266]

too bad that the tube is faulty.

[@dab745]

jackleg Gotcha, I am a big fan of Mullard.

[@umajunkcollector]

put some CFLs in there, then play LIGHT MY FIRE

[@MuscleDad420]

Junk NOS tubes.

[@jackramey3456]

Why did you refer to this amp as a "clone"?

[@josephtravers777]

It's not original. I may be wrong but it looks like a Twin cabinet. I owned an original back in the 80's and if memory serves me well, the cabinet is just a bit taller.

[@fenderstratguy]

“...make a sketch or get a schematic...” or take some pictures with your iPhone

[@Tonetwisters]

Hey. Some of us don't have those things!! :-)

[@fenderstratguy]

Digital camera then? $30 all day long on Craigslist for a super nice one that would have cost you $400 8 years ago.

[@priceamp]

No need to replace original sockets. Just tighten the tube pins and install some tube spring retainers for $2 each. Just IMO.