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Post by aamicrophones on Feb 3, 2017 22:29:15 GMT -6
Dave here from Advanced Audio Microphones
This is the first member of our "T" Series tube microphones. The electronics is based on the traditional M269/M49 AC701 tube circuit. It uses the U48/M269 pattern switching method.
I changed some circuit values to optimize the operation for a GE/JAN 5654W pentode wired as a triode. It easily drives our BV18 transformer which has an 8:1 ratio.
The BV18 just squeezes into the bottom bell housing. You can see that the 7 pin tube can be replaced easily without needing a soldering iron. We use the BV18 in our CM251 and M49.
The CM48T has our AK47 capsule which is in our CM48FET, CM49 and CM47VE microphones. We were able to fit all this including the switch platform into our CM48FET/CM87fet body.
Like the U48, U67 and M269 the AK47 capsule is also wired passively (no rear diaphragm polarization in Cardiod). The rear diaphragm is polarized for Fig 8 and grounded for OMNI.
All resistors are 1% metal film all capacitors have 5% tolerance except for the capsule coupling capacitor which is a 1% polystyrene. The CM48T kit sells for $595.
The CM48T has a -10db pad and a 100hZ HP filter.
I just put one up in the studio against a TLM103 our CM87 and our CM414 and I will record some tracks on the weekend.
Cheers, Dave aamicrophones.com
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Post by hadaja on Feb 4, 2017 4:44:10 GMT -6
Is there a special RGO price n this?
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Post by kcatthedog on Feb 4, 2017 5:53:07 GMT -6
Impressive Dave: great to hear some clips and impressions !
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Post by ericn on Feb 4, 2017 10:18:27 GMT -6
Man and to close to TAX time!
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Post by topshelfmg on Feb 4, 2017 14:11:54 GMT -6
I had an opportunity to hear the prototype at Summer NAMM, and it sounds fantastic.
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Post by hadaja on Feb 4, 2017 16:24:37 GMT -6
So why the use of the ak47 capsule instead of a more traditional 67 style capsule for the m269/u67 sounding mic?
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Post by aamicrophones on Feb 4, 2017 18:32:34 GMT -6
Is there a special RGO price n this? Hi Guys, Yes I will offer RGO members a 10% discount on the CM48T. Use the Promo Code "TenTen" when you get to the pay now page. We also offer a 10% discount on pairs of CM48T and if you buy a pair I will offer and extra 5% discount for RGO members by using the Promo Code "FOD" (friends of Dave). I cannot offer this discount on our new MT8016 as at this point as we break even after we sell 50 units at the $995 cost. Our start-up cost was a lot more to design the preamp. To keep the price competitive I had to buy pots, switches, capacitors, IC's, capacitors, connectors and power supply parts in lots of 1000 units. We bought audio transformers, Vu meter, circuit boards and the chassis in lots of 50 units. The circuit boards and metalwork for the MT8016 is all made in Canada. Once we sell the first 50 units then we can re-access our cost and hopefully offer RGO folks a discount.
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Post by aamicrophones on Feb 4, 2017 18:39:00 GMT -6
So why the use of the ak47 capsule instead of a more traditional 67 style capsule for the m269/u67 sounding mic? Hello, we are using the AK47 capsule in the CM48T. In the CM269T we use our AK67 capsule. I have so far only built up one prototype CM269T and was very pleased with the results. The CM48T's are production models and the CM269T is just a prototype at the moment. The CM269T is out for evaluation at the moment and I will report back. We will not have the sleeve metalwork to build the CM269/67 and the CM414T for another 8-10 weeks. The idea is to make a "T" series with the AK47 capsule, the AK67 and the AK12 capsule that all sell for the $595 price. I am going to build up a CM414T prototype this week. Cheers, Dave
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Post by aamicrophones on Mar 7, 2017 16:42:14 GMT -6
Dave here from Advanced Audio Microphones
This is the first member of our "T" Series tube microphones. The electronics is based on the traditional M269/M49 AC701 tube circuit. It uses the U48/M269 pattern switching method.
I changed some circuit values to optimize the operation for a GE/JAN 5654W pentode wired as a triode. It easily drives our BV18 transformer which has an 8:1 ratio.
The BV18 just squeezes into the bottom bell housing. You can see that the 7 pin tube can be replaced easily without needing a soldering iron. We use the BV18 in our CM251 and M49.
The CM48T has our AK47 capsule which is in our CM48FET, CM49 and CM47VE microphones. We were able to fit all this including the switch platform into our CM48FET/CM87fet body.
Like the U48, U67 and M269 the AK47 capsule is also wired passively (no rear diaphragm polarization in Cardiod). The rear diaphragm is polarized for Fig 8 and grounded for OMNI.
All resistors are 1% metal film all capacitors have 5% tolerance except for the capsule coupling capacitor which is a 1% polystyrene. The CM48T kit sells for $595.
The CM48T has a -10db pad and a 100hZ HP filter.
I just put one up in the studio against a TLM103 our CM87 and our CM414 and I will record some tracks on the weekend.
Cheers, Dave aamicrophones.com
Hi Guys, here finally is a link to the first set of clips. Set-up is a CM48T (bottom) TLM103 (right) CM87 (top) and the CM414 (bottom).
All microphones are in Cardiod as the TLM103 is cardiod only.
The individual vocal, guitar and harmonic tracks were back 18" from the microphones to eliminate any proximity effect and create a consistent source.
advancedaudio.ca/pages/aa-mic-shootout-with-cm48t-cm87-cm414-vs-neumann-tlm103
The drums and percussion I threw on the end was recorded 8' away from the microphones.
View Attachment
Here is a shot from the rear of the microphones and you can see where Lach sat on the stool with the guitar and how far back in the room the drums were.
The microphone preamps are four of our new MT8016 transformer coupled preamps. You can see where the gains are set and that they are flat no HP.
The outputs of the MT8016 preamps where patched directly into the Radar/Studio converters on Tracks 17 thru 20 and sampled at 48khz/24bit.
The posted files are a digital copy of tracks 17-20. The only editing are pauses that I took out between the different source material.
You should be able to lay the files into tracks and switch between them as its just one performance recorded with 4 microphones.
Interestly, the TLM103 sounds more respectful through our preamp than it does through a more modern transformerless preamp to my old ears.
The TLM103 has a K67 response with a transformerless IC circuit with some Neumann de-emphasis built in to compensate for the K67/87 rise.
The CM48T is a traditional signal stage class "A" tube circuit with our AK47 capsule and no de-emphasis just like the original U48 circuit.
The CM87 has our AK67 capsule which has less upper midrange and high end rise than the K67/87 and can be used without de-emphasis.
The CM87 circuit has the same transformer coupled, class "A" Fet/emitter follower circuit as our CM414 and has 14db more headroom than a U87.
The CM414 has our AK12 capsule and the 2 stage transformer coupled, Fet/emitter follower circuit exactly like the original C414eb.
I am going to be recording a demo of some African/World Music in early April and I will be putting the CM48T on several sources.
Cheers, Dave aamicrophones.com
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Post by Vincent R. on Mar 7, 2017 21:22:48 GMT -6
I actually really like the sound of the CM414.
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Post by aamicrophones on Mar 8, 2017 15:45:20 GMT -6
Hi Vincent, thanks!!! The room is only temporarily treated so I think the CM414 tends to work well being further away from the source. There are no flutter echo's but there is still a slight "honk" in the lower mids.
The CM414 also works really well on the piano and its my goto percussion microphone. However, the CM48T "rocked" on upgright bass. I will edit the upright bass solo from a live recording I did with the CM48T when I get a chance.
In haste, back to the workbench there are several microphones calling.
Cheers, Dave
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Post by aamicrophones on Mar 8, 2017 15:46:06 GMT -6
Hi Vincent, thanks!!! The room is only temporarily treated so I think the CM414 tends to work well being further away from the source. There are no flutter echo's but there is still a slight "honk" in the lower mids.
The CM414 also works really well on the piano and its my goto percussion microphone. However, the CM48T "rocked" on upgright bass. I will edit the upright bass solo from a live recording I did with the CM48T when I get a chance.
In haste, back to the workbench there are several microphones calling.
Cheers, Dave
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Post by Vincent R. on Mar 8, 2017 19:09:46 GMT -6
Hi Vincent, thanks!!! The room is only temporarily treated so I think the CM414 tends to work well being further away from the source. There are no flutter echo's but there is still a slight "honk" in the lower mids. The CM414 also works really well on the piano and its my goto percussion microphone. However, the CM48T "rocked" on upgright bass. I will edit the upright bass solo from a live recording I did with the CM48T when I get a chance. In haste, back to the workbench there are several microphones calling. Cheers, Dave The CM48T on an upright should sound awesome. Can't wait to hear it.
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Post by dandeurloo on Mar 8, 2017 22:58:42 GMT -6
I actually really like the sound of the CM414. I have used the CM414's on a number of sources. They worked great as drum overheads in my old live room with a low ceiling. They also sound good on acoustic guitars and I have used them inside a piano with success. They are cool mics.
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Post by Deleted on Sept 10, 2017 12:46:24 GMT -6
About to start recording lots of acoustic guitar (mainly strummed rhythm and fingerstyle Folk) with my CM48T this week, into a Chandler TG2 pre. Aiming to start simple with just one mono mic (the AA), and experimenting with position, distance, polar pattern, HPF on or off, and the 300/1200 impedance switch on the TG2, for the "best" sound/working out the various tones the combo is capable of. (I seem to remember on spoken word the 300 ohm sounded more coloured, but in a good way, Dave what would you recommend?) Then recording in earnest begins!
I've had the mic a few months (it's from the first batch) but only done a few little tests on guitar and spoken word so far. I really like how it sounds for the most part, hate to use the term but very "coloured" and "vintage". I should note I've had very little experience with mics in general, only other tube mic I owned was an MXL V69ME years ago, but from what I remember, this blows it out of the water.
Excited!
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Post by Vincent R. on Sept 11, 2017 7:49:34 GMT -6
I can't speak to the CM48T on guitar, but it was really nice on vocals. It didn't sound exactly like the FLEA 47 I had it up against. It was a bit more neutral with a darker top end, but still a really nice sound. I also had a version of the mic with a BV8, vintage style transformer. Of course, I was going for a vintage vocal vibe. Hopefully I'll get that shoot out edited this month.
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Post by ChaseUTB on Sept 12, 2017 14:19:09 GMT -6
I can't speak to the CM48T on guitar, but it was really nice on vocals. It didn't sound exactly like the FLEA 47 I had it up against. It was a bit more neutral with a darker top end, but still a really nice sound. I also had a version of the mic with a BV8, vintage style transformer. Of course, I was going for a vintage vocal vibe. Hopefully I'll get that shoot out edited this month. What type of singing / harmonizing is that called at 2:15-2:35 ? Is that scat/ skat singing?
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Post by tasteliketape on Sept 12, 2017 14:29:22 GMT -6
Hear ya go Chase ,scat'en at its best Also Very nice Vince as always
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Post by Vincent R. on Sept 12, 2017 17:07:29 GMT -6
I can't speak to the CM48T on guitar, but it was really nice on vocals. It didn't sound exactly like the FLEA 47 I had it up against. It was a bit more neutral with a darker top end, but still a really nice sound. I also had a version of the mic with a BV8, vintage style transformer. Of course, I was going for a vintage vocal vibe. Hopefully I'll get that shoot out edited this month. What type of singing / harmonizing is that called at 2:15-2:35 ? Is that scat/ skat singing? Yup, scatting.
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Post by Deleted on Sept 14, 2017 5:15:43 GMT -6
I did some more tests on acoustic guitar today, strummed and fingerstyle. Just checking the differences between Omni and Cardioid modes on the mic, and 300 or 1200 ohm impedance on the Chandler TG2 pre. I kept the position (12th fret), angle (45 degrees towards fingers/sound hole) and distance (50cm/20") the same, the HPF engaged in all tests, and the pre set to 50dB of gain. Results with Omni vs. Cardioid were unsurprising, the omni mode having less gain, picking up more room, and sounding less distinct overall. Cardioid sounded way better balanced with better tonality overall, for "pop" style recording, although I can see the Omni mode working well for some things, for a deliberately "roomy" sound. The next test I want to do here is trying to get in much closer in Omni mode to see how that sounds, maybe half the current distance. Results with 1200 vs. 300 ohm impedance on the TG2 pre were very interesting. The 1200 setting sounded overall more natural/like the guitar in the room, very nice tonality on both strummed and fingerpicked. When switching to 300 the difference was pretty astounding. Gain is higher, the sound is more strident, with more upper mids, and more "tubey" overall, perhaps better for "featuring" a sound. Although not as natural, it was very coloured in a pleasant way. Conclusions for recording the acoustic in the near future are to stick with Cardioid at 1200 for most things, and venture into Omni or 300 for particular effect. So, it's nice to have options, although not too many! I think I'm gonna try the closer distance with Omni mode now...
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Post by Deleted on Sept 14, 2017 5:44:08 GMT -6
Did it! OK, Omni up much closer (as close as I could get to the 12th fret while still being comfortable to play, and then backing off a little, around 10cm/4"), sounds A LOT better than the more distant first test, at least in my room. With 1200 ohms it sounded natural for the most part, but with an extended and boosted low end (proximity effect, even in Omni??? would need to EQ it out). But the revelation was switching to 300 ohm where for some reason everything fell very nicely into place, bass boominess was gone, more sparkle was there etc. sounded particularly great for fingerpicking. So I guess my go to settings for recording are gonna be more distant Cardioid at 1200 for natural strumming and very close up Omni at 300 for fingerstyle. Hope no one minds me ranting all this stuff here. I am very happy with this mic! It's hard not having another guitarist here so I can sweep the mic around with headphones on while they play to find the best spot, but I will hopefully have the opportunity to do that soon.
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Post by Deleted on Sept 14, 2017 6:05:37 GMT -6
With more listening to all the files, I'm definitely preferring Cardioid at 50cm with 300 ohm on just about everything. The close Omni has too much finger/string/scrapey noise, and the 1200 settings just don't have as much bite. It's nice to have narrowed down a "set and forget" setting which I know will usually bring good results!
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Post by Vincent R. on Sept 14, 2017 7:35:47 GMT -6
Sharing experiences is not ranting...... says the guy who continually posts his YouTube videos and mic test trials. :-P
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Post by hadaja on Jan 7, 2018 4:08:04 GMT -6
So has cm48T changed in any way since its first release? Thanks
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Post by Vincent R. on Jan 7, 2018 7:32:11 GMT -6
So has cm48T changed in any way since its first release? Thanks I am not sure. I do know that they are revamping the CM47VE and CM49. I do not know if they will be taking any of the changes for the CM47VE and incorporating them into the CM48T. Either way, these changes won’t really be seen until the late spring or summer.
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