R
Rev E
New member
Just ordered a matched pair of NOS 6072s for the V69 and Sebatron mic pre. I'll try to get back to you guys as to how things sound.
malcolm123
New member
Rev E said:
I am also about to go Tube shopping. I think I will wait to see what you come up with first.
Im liking what Im reading about the Mullards. I think 4004s or something like that.
Malcolm
G
Gus
New member
First, Flatpicker made me aware of this site.
The v69 uses both halfs of the tube in parallel 12at7?. It is set up kind of like the fet in the KM84. This also helps with noise.
the gain is the openloop gain of the tube in parallel with the capsule capactence/by the feedback cap from Plate to Grid
Most MXL capsule seem to be about 55pf the feedback cap is 56 pf ceramic So the circuit has a gain of about -1 and a very high headroom. With all that feedback the microphonics and noise of the tube are more important that the tube number. I think you would call this an anode follower charge amp.
100kplate R and cathode bypassed Cathode R I forget the value off hand. The PS at the top of the Plate R is about 200V IIRC.
I own two I changed the feedback cap the cathode bypass cap and the output cap from the plate to better ones.
I am guessing but this might be like the tube circuit in the neumann M147.
If you want more tube sound maybe one could reduce the 56pf feedback to say 20pf this would be about a gain of 3 about 10dB.
Being a charge amp input this allows the tube to be mounted in the microphone like it is.
Gus
The v69 uses both halfs of the tube in parallel 12at7?. It is set up kind of like the fet in the KM84. This also helps with noise.
the gain is the openloop gain of the tube in parallel with the capsule capactence/by the feedback cap from Plate to Grid
Most MXL capsule seem to be about 55pf the feedback cap is 56 pf ceramic So the circuit has a gain of about -1 and a very high headroom. With all that feedback the microphonics and noise of the tube are more important that the tube number. I think you would call this an anode follower charge amp.
100kplate R and cathode bypassed Cathode R I forget the value off hand. The PS at the top of the Plate R is about 200V IIRC.
I own two I changed the feedback cap the cathode bypass cap and the output cap from the plate to better ones.
I am guessing but this might be like the tube circuit in the neumann M147.
If you want more tube sound maybe one could reduce the 56pf feedback to say 20pf this would be about a gain of 3 about 10dB.
Being a charge amp input this allows the tube to be mounted in the microphone like it is.
Gus
malcolm123
New member
Welcome Gus.
Great post, but Greek to most around here. LOL
So whats a good tube mod for a V69?
How would one benefit by the mod?
How much difference would there be ?
And again.. Welcome !!!
oh, And Thanks FLAT for informing Gus
Malcolm
Great post, but Greek to most around here. LOL
So whats a good tube mod for a V69?
How would one benefit by the mod?
How much difference would there be ?
And again.. Welcome !!!
oh, And Thanks FLAT for informing Gus
Malcolm
G
Gus
New member
IMO the tube type used in the v69 is OK. I would try NOS 12at7s,12ay7/6072 GE 5 star. The way the tube is used minimizes any tube sound.
The input section has alot of headroom and is being used with alot of feedback . The part that makes the biggest difference in this circuit is the 56pf feedback cap. You want a good low noise 12at7 or 12ay7/6072. IMO more of the sound or lack of tube sound in this microphone is caused by that cap and feedback and not the tube.
For a little more tube sound you can reduce the feedback cap value but not to much so you don't overload the SS section.
With the stock microphone I believe you hear more of the capsule and grill then the electronics. I have modded a number of mxl67 with tube and SS circuits with good parts and the v69 and modded v67s sound very close. IMO the stock electronics in the V69 are OK for the price.
The input section has alot of headroom and is being used with alot of feedback . The part that makes the biggest difference in this circuit is the 56pf feedback cap. You want a good low noise 12at7 or 12ay7/6072. IMO more of the sound or lack of tube sound in this microphone is caused by that cap and feedback and not the tube.
For a little more tube sound you can reduce the feedback cap value but not to much so you don't overload the SS section.
With the stock microphone I believe you hear more of the capsule and grill then the electronics. I have modded a number of mxl67 with tube and SS circuits with good parts and the v69 and modded v67s sound very close. IMO the stock electronics in the V69 are OK for the price.
malcolm123
New member
Gus,
Thanks for the info. Thats cool that you modded a V67. You say it came close but not quite there. Do you think you could have put more money into the modding and make the V67 surpase the V69?
Im asking because I would love to mod my V67g. Especially if I could get a better sound than the V69. I now I could just buy a better mic, but by the time I get to that price range Im thinking I could have modded a V67g and be just as happy.
What would be your dream mod for a V67g saying that you already have the mic and some $$ to throw into it?
Malcolm
Thanks for the info. Thats cool that you modded a V67. You say it came close but not quite there. Do you think you could have put more money into the modding and make the V67 surpase the V69?
Im asking because I would love to mod my V67g. Especially if I could get a better sound than the V69. I now I could just buy a better mic, but by the time I get to that price range Im thinking I could have modded a V67g and be just as happy.
What would be your dream mod for a V67g saying that you already have the mic and some $$ to throw into it?
Malcolm
Teacher
New member
just got my telefunken 12Ax7 ecc83
it completely changed the sound of my CAD m9, for vocals it was very hi fi to the point of sibilance depending on how bad the mic technique and sorta thin
to big and heavy sounding but still hi fi but not as sibilant prone..
needless to say i think it was a good investment.
it completely changed the sound of my CAD m9, for vocals it was very hi fi to the point of sibilance depending on how bad the mic technique and sorta thin
to big and heavy sounding but still hi fi but not as sibilant prone..
needless to say i think it was a good investment.
Marik
Pro Microphone Design
<Im asking because I would love to mod my V67g. Especially if I could get a better sound than the V69.>
Malcolm, how better? As Gus has wrote already, the sound of the V67 (as V69) is limited by capsule and grill. I moded this mic into tube for someone. The project turned to be price-no-object one. We ended up getting Blue-Kiwi capsule, and then it became apparent that the grill and capsule suspension are a problem, so I had to rebuild the suddle and grill as well. In PSU, which is a very important part, I used polipropylene capacitors for B+, and voltage regulators for filaments. If you want to get a nice mic I would suggest to get capsules from J. Peluso. Although I did not have chance to listen to his AKG style one, I heard a lot of very good things about it, and I have his Neumann style, and think that it has a very good value for $160.
Malcolm, how better? As Gus has wrote already, the sound of the V67 (as V69) is limited by capsule and grill. I moded this mic into tube for someone. The project turned to be price-no-object one. We ended up getting Blue-Kiwi capsule, and then it became apparent that the grill and capsule suspension are a problem, so I had to rebuild the suddle and grill as well. In PSU, which is a very important part, I used polipropylene capacitors for B+, and voltage regulators for filaments. If you want to get a nice mic I would suggest to get capsules from J. Peluso. Although I did not have chance to listen to his AKG style one, I heard a lot of very good things about it, and I have his Neumann style, and think that it has a very good value for $160.
F
Flatpicker
...
I think what Gus meant was the original circuit of the V67 doesn’t do anything special compared to a modified one. From what he's told me, the V67 is one of his (if not "the") favorite mics to modify.Marik said:
I dropped Scott Dorsey's board into a Cascade mic (the one that looks like a Marshall 2001), which I’m sure uses the same Shanghai capsule as the V67G, and the difference was night and day. Of all the mics I’ve owned or tried, it’s still my all around favorite for vocals. I can only imagine how good it would sound as a tube mic!
T
tdukex
Man of the Muse
You guys are making me want to go take a basic electronics class so I can start doing some of this stuff myself. Any suggestions on how someone might relatively quickly acquire the knowledge and skill to be comfortable performing some of these basic and intermediate mods?
Teacher
New member
well changing the tube is as easy as changing a light bulb...no skil required for that
T
tdukex
Man of the Muse
Teacher said:
I'm asking about mic mods, not changing a tube.
Teacher, you seem to have a penchant for being an unimaginitive, slow-witted ass. Perhaps if you were more comfortable with your own intelligence (or lack thereof), you could muster enough self respect to refrain from making such asinine, condescending comments.
Teacher
New member
tdukex said:
replacing a tube is not a modification to a mic?
did I fukk your girl or something?
T
tdukex
Man of the Muse
Teacher said:replacing a tube is not a modification to a mic?
No more than replacing a light bulb is a mod to a light fixture ... no skil required for that
T
tdukex
Man of the Muse
Teacher said:
did I fukk your girl or something?
No, but I'm going to enjoy fukking you if you stubbornly and stupidly insist on acting like a little weenie and making insipid comments following my posts on this BBS.
Marik
Pro Microphone Design
Gentlemen,
It is a very broad topic, and everyone understands and should understand the meaning of 'mod' his or hers own way. I would say changing the tube or replacing caps and resistors is an upgrade. Mod would be changing internal structure of the circuit. But it is really doesn't matter. We all know what we are talking about, so let's get back to mic mods.
It is a very broad topic, and everyone understands and should understand the meaning of 'mod' his or hers own way. I would say changing the tube or replacing caps and resistors is an upgrade. Mod would be changing internal structure of the circuit. But it is really doesn't matter. We all know what we are talking about, so let's get back to mic mods.
Teacher
New member
tdukex said:
o please sir don't run me out of home rec .com
Teacher
New member
Marik said:
thank you for the clarification...i was using the term upgrade and modification interchangeably(sp?)
T
tdukex
Man of the Muse
Teacher said:o please sir don't run me out of home rec .com
Why, no, sir. That is not my intention.
I just don't like snide comments being made after my posts by people I percieve to be assholes. If I am wrong about you, I sincerely apologize. If I am right, at least now we know what to expect from each other.
On with the thread.
H
Han
New member
Marik said:
I was searching for the V69 and stumbled upon this thread.
My V69 is a bit noisier than it used to be, kind of a 100hz hum, so I opened it and found out it doesn't have the 12AT7, but a rather small tube which is soldered to the circuit board.
There's a clip with two small screws over the tube, so I couldn't see the type of it. Do I have kind of a special version of the V69 Mogami?
Does anybody know where this noise is coming from, can it be the power supply?
Thanks!