[ACM investiupgradifications] All things MICROPHONE
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josan
Well-known member
No sag and I used them on a session already (AC3 and AC200). I will probably trade out the transformers but I was quite happy with the stock sound. Of the two I prefer the AC3 as the electronics in the AC200 require that I put the pad on (for a ribbon!) but as a figure 8 it really would be a great bluegrass mic. The electronics are a black smudge though with smd's
so I figure a bypass switch is in order and a new transformer.
so I figure a bypass switch is in order and a new transformer.
Ptownkid
Well-known member
how do you correctly disassemble the ac3's?
josan
Well-known member
Remove all the screws, the top comes right off and the bottom is hooked up to the transformer. The ribbon part slides so either desolder the leads or remove the keeper on the barrel of the xlr jack, transformer comes out through top. Haven't sized for new transformers but maybe the cinemag
9887 or 9888 uncanned may fit or the rmx1 edcor
9887 or 9888 uncanned may fit or the rmx1 edcor
Kaspar
Active member
I put an Edcor RMX1 in my ACM3. I'm happy with the results and at $22.77 I think it's well worth it. The stock tranny wasn't terrible sounding but the difference in construction was well.... staggering.
Marik
Well-known member
[quote author="rodabod"][quote author="rodabod"]
I also just bought a military equivalent CV4003 so I will check its noise performance too and report back.[/quote]
I'm just testing and burning this in just now. It seems to have lower noise than the noise-selected GE 6072 which I was using although it is hard to compare since the output levels are different.
Sound quality seems fine, and low-end extension is fine too. What I'd really like to do though is take a Lindos test-set and compare responses using the different valves I have.
For reference, the CV4003 (ECC82) is a Mullard with a KQDD stamp and has the date code 85-09 which I think makes it a late production. They also made an ECC802S which is noise-selected.
Roddy[/quote]
Hi Roddy,
If you have some low noise ECC82 that would be interesting to try with a more suitable transformer ratio somewhere around 6:1 (maybe even BV8?). IIRC, G.deGeer uses that tube in his mics.
[quote author="Kaspar"]I put an Edcor RMX1 in my ACM3. I'm happy with the results and at $22.77 I think it's well worth it. The stock tranny wasn't terrible sounding but the difference in construction was well.... staggering.[/quote]
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.0002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M
I also just bought a military equivalent CV4003 so I will check its noise performance too and report back.[/quote]
I'm just testing and burning this in just now. It seems to have lower noise than the noise-selected GE 6072 which I was using although it is hard to compare since the output levels are different.
Sound quality seems fine, and low-end extension is fine too. What I'd really like to do though is take a Lindos test-set and compare responses using the different valves I have.
For reference, the CV4003 (ECC82) is a Mullard with a KQDD stamp and has the date code 85-09 which I think makes it a late production. They also made an ECC802S which is noise-selected.
Roddy[/quote]
Hi Roddy,
If you have some low noise ECC82 that would be interesting to try with a more suitable transformer ratio somewhere around 6:1 (maybe even BV8?). IIRC, G.deGeer uses that tube in his mics.
[quote author="Kaspar"]I put an Edcor RMX1 in my ACM3. I'm happy with the results and at $22.77 I think it's well worth it. The stock tranny wasn't terrible sounding but the difference in construction was well.... staggering.[/quote]
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.0002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M
mushy
Well-known member
- Joined
- Jan 20, 2008
- Messages
- 680
[quote author="Marik"]
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M[/quote]
1. Thanks for the info, Marik
2. What transformer do you like? (Cinemag, Lundahl, Tab-Funk, other?)
3. Tell us more about your toroids. Are they available for consumption?
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M[/quote]
1. Thanks for the info, Marik
2. What transformer do you like? (Cinemag, Lundahl, Tab-Funk, other?)
3. Tell us more about your toroids. Are they available for consumption?
Marik
Well-known member
[quote author="mushy"][quote author="Marik"]
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.0002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M[/quote]
1. Thanks for the info, Marik
2. What transformer do you like? (Cinemag, Lundahl, Tab-Funk, other?)
3. Tell us more about your toroids. Are they available for consumption?[/quote]
The reason I started making my own transformers for ribbons was because I did not like Cinemag and Lundahl (I don't think Oliver of Tab-Funk makes any). The main problem is either has too much of winding resistance and noise. The Lundahl with Rpri=0.02 ohm, Rsec=59 Ohm, with 0.1 Ohm ribbon and 2K load results in NF(noise figure)=1.92db . Considering its high secondary DCR we also have some loss there due to the signal loading.
Cinemag has even higher primary resistance of 0.12 Ohm, but since the transformer ratio is not as high it somewhat offsets the worsen noise. On the other hand, it does not have ideal impedance matching and is more suitable for long narrow ribbons. Besides, I believe its DU core is not the most suitable for optimised ribbon transformer.
Both Cinemag and Lundahl calculate their ribbon transformers way overkilled on low frequencies. It results in much higher number of turns, with too much of copper resistance and noise.
I use toroidal cores wound with either Amorthous, or 80% Ni thin ribbons (as opposed to stacked toroids).
One of my early prototypes had Rpri=0.0002 Ohm, Rsec=8.5 Ohm, which with Rsource=0.1 Ohm and Rload=2K results in NF=0.72db.
Just for fun I made a transformer when I could not measure primary DCR on my either Genrad 1650 bridge, or HP 3457 (with Kelvin probes). With ratio 1:37 the secondary DCR was only 0.9 Ohm (!!!).
Of course, I can make any ratio, or custom fit for a certain ribbon.
If there is enough interest and demand I could think about making them commercially.
Best, M
I am surprised to see good results with that transformer. There is not much info on it, but its EXTREMELY high pri DCR of 0.4 Ohm (!!! :shock: :shock: :shock: ) suggests high noise. The stock DCR is "only" 0.09 Ohm. For comparison, my own torroidal transformers on primary have 0.0002 Ohm.
It is quite hard to make a decent low noise EI transformer.
Best, M[/quote]
1. Thanks for the info, Marik
2. What transformer do you like? (Cinemag, Lundahl, Tab-Funk, other?)
3. Tell us more about your toroids. Are they available for consumption?[/quote]
The reason I started making my own transformers for ribbons was because I did not like Cinemag and Lundahl (I don't think Oliver of Tab-Funk makes any). The main problem is either has too much of winding resistance and noise. The Lundahl with Rpri=0.02 ohm, Rsec=59 Ohm, with 0.1 Ohm ribbon and 2K load results in NF(noise figure)=1.92db . Considering its high secondary DCR we also have some loss there due to the signal loading.
Cinemag has even higher primary resistance of 0.12 Ohm, but since the transformer ratio is not as high it somewhat offsets the worsen noise. On the other hand, it does not have ideal impedance matching and is more suitable for long narrow ribbons. Besides, I believe its DU core is not the most suitable for optimised ribbon transformer.
Both Cinemag and Lundahl calculate their ribbon transformers way overkilled on low frequencies. It results in much higher number of turns, with too much of copper resistance and noise.
I use toroidal cores wound with either Amorthous, or 80% Ni thin ribbons (as opposed to stacked toroids).
One of my early prototypes had Rpri=0.0002 Ohm, Rsec=8.5 Ohm, which with Rsource=0.1 Ohm and Rload=2K results in NF=0.72db.
Just for fun I made a transformer when I could not measure primary DCR on my either Genrad 1650 bridge, or HP 3457 (with Kelvin probes). With ratio 1:37 the secondary DCR was only 0.9 Ohm (!!!).
Of course, I can make any ratio, or custom fit for a certain ribbon.
If there is enough interest and demand I could think about making them commercially.
Best, M
mushy
Well-known member
- Joined
- Jan 20, 2008
- Messages
- 680
How's the frequency response? What do they sound like? Will they fit into an ACM-3? Are they rf shielded? What would be the price point? How much interest would be enough interest?
Chance just mentioned that there was some custom transformers on the way. I'm looking forward to the details.
Chance just mentioned that there was some custom transformers on the way. I'm looking forward to the details.
Marik
Well-known member
[quote author="mushy"]How's the frequency response? What do they sound like? Will they fit into an ACM-3? Are they rf shielded? What would be the price point? How much interest would be enough interest?
Chance just mentioned that there was some custom transformers on the way. I'm looking forward to the details.[/quote]
Both Amorthous and Hi Nickel cores sound very clear, open, and transparent. The bass is much less muddy. They are somewhat different in timbre from each other due to core material differences.
Amorthous core will fit into ACM-3. If needed, it is not a problem to make rf shielding for extra. I don't think however, it is necessary, as I did not have any problem even in my basement (!!!), which for some reason is particularly bad. In any case, usually (depending on material), the microphone body is sufficient for shielding.
As for the price point, since they are premium transformers I highly doubt they going to be very cheap. It will also depend on quantities and demand. I can make very limited quantities by hand, otherwise, I need to send it to facility. The core prices (esp. lately) are way up for both Ni and Amorthous.
I could probably make and post some tracks to compare those against Lundahl and Cinemag.
Best, M
Chance just mentioned that there was some custom transformers on the way. I'm looking forward to the details.[/quote]
Both Amorthous and Hi Nickel cores sound very clear, open, and transparent. The bass is much less muddy. They are somewhat different in timbre from each other due to core material differences.
Amorthous core will fit into ACM-3. If needed, it is not a problem to make rf shielding for extra. I don't think however, it is necessary, as I did not have any problem even in my basement (!!!), which for some reason is particularly bad. In any case, usually (depending on material), the microphone body is sufficient for shielding.
As for the price point, since they are premium transformers I highly doubt they going to be very cheap. It will also depend on quantities and demand. I can make very limited quantities by hand, otherwise, I need to send it to facility. The core prices (esp. lately) are way up for both Ni and Amorthous.
I could probably make and post some tracks to compare those against Lundahl and Cinemag.
Best, M
[quote author="Marik"]If you have some low noise ECC82 that would be interesting to try with a more suitable transformer ratio somewhere around 6:1 (maybe even BV8?). IIRC, G.deGeer uses that tube in his mics.[/quote]
Do you think loading the output a little more would actually be beneficial?
From what I can hear, the lower output impedance hasn't affected the response of the transformer noticeably, and I assume distortion should hopefully be less with the lower output.
I might be interesting to try though, as I have a few other transformers I could use.
Do you think loading the output a little more would actually be beneficial?
From what I can hear, the lower output impedance hasn't affected the response of the transformer noticeably, and I assume distortion should hopefully be less with the lower output.
I might be interesting to try though, as I have a few other transformers I could use.
CHANCE
Well-known member
Re: HERE WE GO AGAIN (gear group buys) [message #384092 is a reply to message #226785 ] Fri, 07 November 2008 08:14
compasspnt
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Registered: December 2004
Location: Compass Point Studios, Na...
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NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.
compasspnt
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Registered: December 2004
Location: Compass Point Studios, Na...
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NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.
Marik
Well-known member
[quote author="CHANCE"]Re: HERE WE GO AGAIN (gear group buys) [message #384092 is a reply to message #226785 ] Fri, 07 November 2008 08:14
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
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remove from buddy list
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NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing?
I spent years of R&D, studying all aspects of ribbon microphones design and manufacturing, including transformers SPECIFICALLY designed and suited for ribbon mics. Considering you never heard them, held in your hands, or even seen them, your remark is quite insulting and undermining. I think it would be nice for you at least sonically compare them to AMI/TAB before saying such things.
Could you post specs on AMI/TAB, including core type and its material, pri and sec DCR, ratio, resonance point, etc.
Thanks, M
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
Diamond Member
remove from buddy list
ignore all messages by this user
NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing?
I spent years of R&D, studying all aspects of ribbon microphones design and manufacturing, including transformers SPECIFICALLY designed and suited for ribbon mics. Considering you never heard them, held in your hands, or even seen them, your remark is quite insulting and undermining. I think it would be nice for you at least sonically compare them to AMI/TAB before saying such things.
Could you post specs on AMI/TAB, including core type and its material, pri and sec DCR, ratio, resonance point, etc.
Thanks, M
CHANCE
Well-known member
[quote author="Marik"][quote author="CHANCE"]Re: HERE WE GO AGAIN (gear group buys) [message #384092 is a reply to message #226785 ] Fri, 07 November 2008 08:14
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
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remove from buddy list
ignore all messages by this user
NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing? .[/quote]
Oh no! Absolutely not! You do supurb work. There are many out there who are seeking to swap xfrmrs blindly and TnC has someone who will make xfrmrs taylored for each mic.
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
Diamond Member
remove from buddy list
ignore all messages by this user
NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing? .[/quote]
Oh no! Absolutely not! You do supurb work. There are many out there who are seeking to swap xfrmrs blindly and TnC has someone who will make xfrmrs taylored for each mic.
Marik
Well-known member
[quote author="CHANCE"][quote author="Marik"][quote author="CHANCE"]Re: HERE WE GO AGAIN (gear group buys) [message #384092 is a reply to message #226785 ] Fri, 07 November 2008 08:14
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
Diamond Member
remove from buddy list
ignore all messages by this user
NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing? .[/quote]
Oh no! Absolutely not! You do supurb work. There are many out there who are seeking to swap xfrmrs blindly and TnC has someone who will make xfrmrs taylored for each mic.[/quote]
Could you provide with more detail as for in WHICH AREAS and HOW it will be taylored for each mic?
As I've already asked, could you post specs on those transformers, including core type and its material, pri and sec DCR, ratio, resonance point, etc.
Any chance for sound clips and comparison to well known transformers (Lundahl, or Cinemag, for example), or at least to a stock one?
Here I have mine modified ACM-3 and stock Stellar RM3 (the same, but rebranded mic) on my voice (pay attention to the noise floor). If your transformers are superior, I would be more than interested.
http://home.comcast.net/~markfuksman/Ribbon1.mp3
http://home.comcast.net/~markfuksman/Ribbon2.mp3
Thanks, M
compasspnt
Messages: 11352
Registered: December 2004
Location: Compass Point Studios, Na...
Diamond Member
remove from buddy list
ignore all messages by this user
NB: Everyone planning to modify one of the TNC recent GB products, please be aware that we are having some special transformers made by the best transformer facility in the world, AMI/TAB-Funkenwerk.
I have a sample right now made for the ACM-3 ribbon that really improves the beast.
So hold off buying some goofy inferior thing, just to be mod-happy.
Details at Eleven.[/quote]
Chance,
With all due respect, do you imply my transformers are not special enough, or I just offered some goofy inferior thing? .[/quote]
Oh no! Absolutely not! You do supurb work. There are many out there who are seeking to swap xfrmrs blindly and TnC has someone who will make xfrmrs taylored for each mic.[/quote]
Could you provide with more detail as for in WHICH AREAS and HOW it will be taylored for each mic?
As I've already asked, could you post specs on those transformers, including core type and its material, pri and sec DCR, ratio, resonance point, etc.
Any chance for sound clips and comparison to well known transformers (Lundahl, or Cinemag, for example), or at least to a stock one?
Here I have mine modified ACM-3 and stock Stellar RM3 (the same, but rebranded mic) on my voice (pay attention to the noise floor). If your transformers are superior, I would be more than interested.
http://home.comcast.net/~markfuksman/Ribbon1.mp3
http://home.comcast.net/~markfuksman/Ribbon2.mp3
Thanks, M
[quote author="ChuckD"]OK I got my Mics on Sunday...
Here is my schematic for the ACM-1200.
It is almost the same as the APEX 460 that someone else posted a long time ago, with the new switches added. Please feel free to make corrections here.
[/quote]
R12 should probably go after the C11-C12 - and attach to the grid of the cathode-follower tube (pin7) for bias.
Jakob E.
Here is my schematic for the ACM-1200.
It is almost the same as the APEX 460 that someone else posted a long time ago, with the new switches added. Please feel free to make corrections here.
[/quote]
R12 should probably go after the C11-C12 - and attach to the grid of the cathode-follower tube (pin7) for bias.
Jakob E.
buschfsu
Well-known member
i have 2 acm3's that need xformer upgrades. i will be curious to hear the differences between these chunks of iron.
thanks
thanks
Well, since this all things TnC mics, here is one for ya'. I received my ACM-1200 and thought it sounded pretty meaty to me, which is sort of not what others have been experiencing from what I have been reading (opinions are all over the map, I know). The only issue I seem to be having is that any 'plosives kill the audio. Audio ramps back up pretty quickly but this is really a bummer and makes the mic unuseable at this point. I put in a new (old) 12ax7 that was tested on one of those old school tube testers and it did not fix the problem as I was hoping it would. I am leaning toward it being a bad diaphragm at this point. You guys got anything else I should look at? I hate to buy a new diaphragm that cost as much as the mic was to begin with.... My luck with anything made in China runs at about a 60 percent success rate in the "does it work out of the box" area I figure. At least my preamps are alive and kicking so far....
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