I have a home-studio for mixing purposes and started thinking about a microphone for dubbing... I was impressed by the MXL69M because it wasn't to bright sounding and has nice low and low-mid response on vocals. I just bought it... it will be arriving within a week.
I heard you could change tubes and that there are 12AT7 and 12AX7 versions... How can I find out which version I have? I saw both 12AT7 and 12AX7 versions from Telefunken in very good condition... I was thinking about changing the stock-tube for one of these.
Hope someone can tell me which tube I need and how the sound would improve.
Thanks! I will look it up... Yeah, I ordered from a store where I know the owner personally. He let me audition the microphone. It sounded great. But I am thinking about swapping tubes to make it even better and more vintage sounding.
I am gonna have a listen. I ordered a siemens ECC81 and telefunken ECC81... Monday or Tuesday next week the microphone and tubes will be delivered... excited!
I am gonna have a listen. I ordered a siemens ECC81 and telefunken ECC81... Monday or Tuesday next week the microphone and tubes will be delivered... excited!
Are you going to record the same source and compare?
I just got the MXL in yesterday and started recording rap-vocals with it. It sounds decent, I think the drive that the tube adds is a little much but then again it was the stock tube. The highs are a little Chinese by my taste but not that big of a problem because it responds very well to EQ.
Today, I got in a Siemens ECC81 and Telefunken ECC81. I put in the Telefunken and all I got was noise. After changing it with the Siemens it was more open in the highs and less warmth in the lows. I actually liked it but it came a little aggressive in the mids.
After 25 minutes, this tube started making crackling noise too... :S
So, I changed back to stock tube to see if it would go away. I had 1 small moment of hearing a crackling noise and is behaving normal again...
I am a little scared to change it back to Telefunken or Siemens tube again because I am afraid of damaging the microphone. Can anyone assist me with some hints, tips etc.
An ECC81, while slightly less gain has a huge current flow, and it just may be too much for the circuit. I have certainly found that its not always a drop in replacement for a 12AX7.
It seems more common to drop in a 6072 (12AY7) for mic circuits. Lower gain yet than ECC81 (12AT7) but is similar in current use and so the load line generally translates better for a circuit designed for a 12AX7.
I dont know the cicuit of that mic very well, so im speaking in generalities.
Its also just possible you got bad tubes. Not sure where you got them, but tubes from ebay or other low cost sources are hit and miss, so if you dont have a tester and are buying just one or two tubes its generally worth the extra $ to go to a professional, like Bowie, and get the hand held deal.
I found a 12AT7 stock tube in it. That's why I chose the ECC81 tubes from Siemens and Telefunken. They were tested by a professional tester and I got the test-reports with the tubes.
Because the stock tube in the microphone is a 12AT7, (I believe ECC81 is the European version, similair to 12AT7) I put in the Telefunken...
Still got the problem but I am going to discuss it with an electrician who works in the studio I freelance a lot.
To the OP .. did you get the problem figured out or solved ? Was curious if there was a solution.
I just picked up two of these on the cheap. So I'll have a couple to play with and compare changes-vs-stock. I'll be taking a look at Jim's previous post.. any other suggestions ? Capsule swap ? The ME editions have a tranny right ? Tranny swap with ? If I come up with anything earth shattering, I'll start a new thread...
I haven't found a solution. (Besides tapping the mic when it starts making noise) I am currently letting a colleague at the studio look at it. He is measuring everything and seeing if I damaged the circuit somehow and seeing if he can change the component where the tube is mounted in if that is necessary.
I made some recordings and mixes with this microphone and if it is working and not making noises, it sounds really good for the price... probably gonna share a .wav file of a part of the song with you guys soon!
I haven't found a solution. (Besides tapping the mic when it starts making noise) I am currently letting a colleague at the studio look at it. He is measuring everything and seeing if I damaged the circuit somehow and seeing if he can change the component where the tube is mounted in if that is necessary.
Bummer. While I dont know if it can help your problem or not - Im about to publish a mod article for the V69 that is pretty in depth. Well as in depth as I could get without schematics. ( I did a drawing for the tube section though ) I thought I had seen a Jim Williams post on the V69 but alas when I looked it up it was for a bluebird. So I was on my own, but there were certainly some surprises I found. Im finishing up some final clips between the modded mic vs the stock one and I should be ready within a week. I have a session on thurs and it may be an opportunity to get some clips with real musicians rather than me playing instruments I dont normally play.
@Tigri. I had a thought. When I was working on my units I noticed that it was real sensitive to having the cover seated and grounding properly. So what I did was use some sandpaper to clean off the the top where it presses upagainst the metal by the headbasket & Screw on the base snugly. That removed any "scratchyness" I was hearing. Thought id mention just in case this is your issue as well.
@Tigri. I had a thought. When I was working on my units I noticed that it was real sensitive to having the cover seated and grounding properly. So what I did was use some sandpaper to clean off the the top where it presses upagainst the metal by the headbasket & Screw on the base snugly. That removed any "scratchyness" I was hearing. Thought id mention just in case this is your issue as well.
Nice. I'll have a look at it soon. Currently not able to look at the mic due to some recording sessions. Although, my colleague is making some progress with the mic. He cleaned the pins of the tube and found a bigger rubber ring to fit around the tube to keep isolation from the metal placeholder. (The european tubes like Telefunken tend to be a bit smaller then the American versions of this one...)
It definitely made the mic sound better. He is still not sure about the noise and if it is gone but he is making progress!
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