I'm using an AKG SolidTube that has begun to behave a little odd.

Sometimes, it suddenly stops working (no sound) and when it seems to work, the sound is very bright (almost no bass at all). It also sounds very distorted. Does this indicate that I need to replace the tube you think?

I am thinking about sending it away to an AKG repair shop but according to the manual it doesn't seem too hard to replace the tube myself.

It says:

[The tube] can now be removed by carefully pushing away the lower part of the elasticated cushioning for the tube and, simultaneously, carefully levering the tube out of the socket with a small flat screwdriver. Inserting a new tube is done in reverse order of the above description.

I'm a total newbie on electronics but this sounds quite easy to me.

I have read about "tube biasing". Is this something I need to care about when replacing a microphone tube? The tube type is ECC-83.

very easy to replace the tube.. only take 10 mins.. no need to return to factory..

bobo

You should have a PM by now trigger

as bobo says, it's very easy - I've also added some info regards removing the internal foam shield if you want to try it...

The user manual explains it well enough. If you are still in doubt ask again and I'll try to do my best.

Thank you for the replies!

I have now ordered a Tung-Sol 12ax7 that I will try to put in there. I will come back to you with the result.

JAN Philips USA 12AX7WA here. Works way better than the stock one. Good luck.

If any "euro-guy" is interested:

https://gearspace.com/board/gearslut...ax7wa-nos.html

There's a lot of tubes that'll work better than stock. You should definitely experiment as some tubes can make it sound like another mic entirely. If your Tung-Sol is an original (not-re-issue) then that's an excellent choice. With tubes, you just want to be careful with the tip as it is fragile and, if the pins get bent, straighten them with needle-nose pliers, not your fingers, to prevent any leaks.

Excellent information regarding the pins. Thanks.

It is a reissue Tung-Sol. Since this is my first time swapping a tube, I don't want to buy something too expensive. Do you have a better suggestion than a Tung-Sol reissue?

Quite a few. Telefunken will give you a very accurate sound. Vintage Tung Sols an RCAs have the classic tube sound; present, big, and saturated. Mullards are extremely smooth and even dark. There's a ton of options. When you get ready to check around, let me know. I sell vintage tubes to folks here for a lot less than the online stores. One more thing, when you pull the old tube out, rock it back and forth gently or, in a circular motion while pulling up. Putting some contact cleaner like Progold on the pins of the new tube is always a good thing too.

Don't buy the vintage tube BS, the reissue will sound as good or better and you'll save a lot of money.

You've made a great choice now get on with using the thing.

This tube-swapping thing turned out to be a quite interesting story.

First, a little background. I'm renting an "abandoned" studio on monthly basis. The studio owner is not using his studio at all, so I'm there on my sparetime doing some recordings.

So, this AKG SolidTube that I had problems with, belongs to the studio. Tonight I walked to the studio to pickup the SolidTube mic and bring it home to swap the tube. But, there is a locker in the studio containing various spare parts. I have never really had a reason to find out what kind of stuff that hides in there. But tonight, I thought that I could take a look for some tubes in there.

Bingo! I found four old Telefunken ECC83 tubes. I have read that these tubes should be quite good. So I opened up the microphone and pulled out the bad tube. And it seemed like this microphone already had been modded because it was a JAN Philips 12ax7WA inside it (also a good tube from what I have heard). And suddenly, some things about the AKG SolidTube started to make sense. This microphone doesn't have a good reputation but I have always used as my go-to vocal mike. And the tube sitting in there is probably the reason to why I like this mike.

Anyway, I swapped the tube for a Telefunken and now it seems to work fine again. I didn't have time for some serious testing tonight but it seemed to work well.

Thanks for all the comments and good advices in here. I will probably write more when I do my next session with this microphone. Maybe some of you are interested... I don't know...

Sir,
put me down the interested people list.

I'm quite curious as to the differences you heard between the various tube replacements.

We've got a SolidTube that is merely collecting dust these days (for good reason) and I'd love some experienced opinions on other tubes to try out.

A nice Mullard smoothes them right out - also, rip out the internal foam from the basket.

Has anyone who has performed the telefunken or similar mod with the solidtube and also had experience with using an AKG 414 and if so how do they compare (mainly on male rock vocal) Which did you feel was better?

Regards
Ross

Hey Ross,

I own a SolidTube with a NOS Telefunken tube in it and used it for male rock vocals on project I did not so long ago. It has a very warm but agressive sound to it and helped the vocals cut right through the mix.

You can hear it in action on all the songs here myspace.com/thewillca

Never been a fan of 414 on vocals, to clean and sterile for me.

SSaudio, I had posed this question earlier and then noticed your comments regarding taking the foam out of the basket on the Solid tube. I had it apart about an hour ago and could not determine how to get the basket off. I did not want to force it for fear damaging something. I did not notice any screws holding the basket on. I pulled gently on it but it was not wanting to come off so I decided to wait to see if anyone had any further info on this procedure. I would like to take the foam out as I have heard numerous comments saying it improves the quality. If you have any other detailed information regarding doing some upgrades it would be great if you can share them. One post I read said something about replacing a 1uf output cap with film and also using a .022 uf film cap for bypass. Any knowledge on this aspect? Thanks

Hi Sonichermit,
I know this is an old post, but if you still need the info or someone else needs it, here it is..
To get the basket off, you need to hold the plastic housing of the tube/electronics and give the basket about an 8mm gentle spin. Be carefull not to over spin it.
This will unlock the basket from the white plastic housing and you will be able to pull the basket away from the white plastic housing.

Hope it helps. Feel free to ask if it doesn't goes smooth..

Very old post but - I'm trying to replace a tube in my Solidtube and trying to twist off the head basket with even a lot of force doesn't move it. Is this an anticlockwise turn to open this mic? Just want to know if I really give it some force (if its a bit stuck) that I wont do any damage.