Advanced Audio MT8016 Dual Channel Preamp
Feb 9, 2017 16:35:02 GMT -6
Johnkenn, dandeurloo, and 3 more like this
Post by aamicrophones on Feb 9, 2017 16:35:02 GMT -6
Hi Guys, Introducing the AA MT8016 Dual Channel Microphone Preamplifier and a quick look at the development and its history.
After several conversations over the years with console designers like our old friend Malcolm Toft who designed the Trident consoles and Tom Graefe who designed consoles for MCI/Sony as well as preamps for Wunder Audio...we came to the conclusion that we liked Malcolm, Tom and the Neve approach that relied on high quality input transformers which do not require a pre-transformer PAD.
Malcolm, Tom and myself all agree that using a PAD in front of the input transformer is frowned upon and can “suck the life out of a preamp”.
I owned and serviced two Trident Series 80B consoles in the 80’s plus a Neve console with 1073 modules.
I am very familiar with their sound and design.
Joseph Magee who is a client of Advanced Audio plus the supervising music mixer at Sony Pictures and the Pitch Perfect movies asked if we could build him a preamp based on the Series 80b console that he cut his teeth on in the 80’s.
Joseph told us he was never able to find a modern replication of the original Series 80b preamp that would give him the “British” sound that he remembered.
I also have never heard any reproductions of the original Series 80b modules that actually captured the original sound like those I used in my years at Ocean Sound in Vancouver.
Our good friend Malcolm Toft along with Chris Potter of Trident Studios were the original designers of the Trident Series 80b plus the A & B range consoles.
I have known Malcolm since 1979 when we bought the first Series 80b at Ocean Sound directly from Trident in the UK.
Malcolm and Chris customized it for our requirements plus we came up with a method to implement Hi/Lo "Q" on the sweep EQ's of the two Series 80b consoles at Ocean.
I also met Malcolm several times over the years at AES conventions where he was showing his latest designs and products.
Malcolm was more than excited to collaborate on the MT8016 design as he felt his considerable contributions to the Pro Audio Industry were being under utilized after he was commissioned to built the ATB Toft series mixer under a stripped down budget. Malcolm not only designed World Class mixers in the 70’s but as an engineer he recorded Hey Jude, David Bowies Space Oddity and James Taylor’s first album.
It was a huge privilege and honour for me to work with Malcolm on the design of the MT8016 preamplifier. Malcolm and I traded schematics and ideas back and forth for just over two weeks before coming up with the initial design implementation. We started in early April of 2016 and Malcolm delivered me the first production model for the Nashville Summer Namm show in late June 2016.
It took us from July 2016 until early December 2016 to fine tune the MT8016 and get the circuit boards and metalwork built in Canada. We can now hand assemble 10 units a month here in our shop.
We are expanding the production facility to be able to produce 20 preamps a month by the end of 2017. At this time we are custom assembling about 25 microphones a month and with the new "T" series tube microphone expect to be custom assembling 40 microphones a month by the end of 2017.
The Trident Series 80b had one of the first transformer coupled IC input stage microphone preamplifiers that we really liked and compared favourably to the Neve 1073. How, Malcolm and Chris accomplished this was by designing two independent op amp gain stages controlled by a dual pot. This clever design increases the headroom and transparency as the two stage work in tandem with each other.
Like the Series 80 and 1073 design the MT8016 has two gain stages controlled by a dual gain element. The Neve design switches in the 2nd gain stage after the 50db position while in the MT8016 the gain of each stage is brought up together optimizing the headroom and signal to noise. Each "op amp" stage in the MT8016 has 30db of maximum gain and the input transformer provides >15db of voltage gain with an overall gain of nearly 75db. The MT8016 gain pot also attenuated the output of the microphone transformer, -10db before the gain stages are activated at the 0db gain position.
Microphone signals from high SPL sources are attenuated after the transformer as indicated by the -10db setting at the start of the gain pot.
Our end goal was to design a "State of the Art” fully transformer coupled preamp with high quality parts for very affordable prices with a vintage look and feel.
Malcolm sourced the input and output transformers for the MT8016 from the same UK Company, OEP that provides transformers for Neve and wound the original Series 80b transformers. The input transformer that Malcolm spec'd had the same ratio and are true to the original 80b specifications but we had the transformers casing changed to be made PC mountable.
The 6:1 ratio input transformer gives us the sound from the MT8016 that we were looking for along with nearly 15db of voltage gain.
When a preamp design has no input pad the “sound” of the input transformer is more audible and “colours” the sound in a really musical way.
The MT8016 has a big transformer sound with great definition.
We were also thrilled to hear the series 80b preamp design with more modern components. We found that we could accomplish this and use electronic components that had better specifications than parts available in the late 70’s. The MT8016 uses OP275 IC’s in the audio path, this IC has twice the slew rate of the original TL071 and the OP275 can drive 600 ohm loads.
The original TLO71 started to suffer with loads great than 5K ohms as Malcolm buffered the output stage in the original Series 80b design with a pair of transistors.
With the OP275 this buffer stage is not required. The front end of the MT8016 circuit has been married to a transformer balanced output stage that further emulates the 70’s British console sound.
I also added a variable HP filter that I have found invaluable in my MCI/Sony MXP3036 that our good friend Tom Graefe designed.
In our experience a variable HP filter is usually all you need to clear up a muddy guitar and reduce pops and thumps without it effecting the vocal warmth.
The MT8016 has high quality toggle switches for phase, phantom power and HP filter engage. All switch positions have status LED's that light when activated. You have immediate visual indication that the phase switch or 48v power or HP filter circuit have been engaged.
The MT8016 also features a large analogue VU meter and a Peak LED above the gain control.
Measured specifications of the MT8016:-
Noise:
E.I.N. < -129dbm 20hz to 20khz input terminated into a 1K load
Maximum output:
+21dbm / +24dbu
Distortion:
1Khz +21dbm: 0.009%
40Hz +21dbm 0.5%
50Hz +21dbm 0.05%
Frequency response:
22Hz to 40kHz +/- 1db.
Gain range: -10 to +60db.
HP filter: 18db/octave variable from 30hz to 350hz
Power supply: 90v a/c to 240v a/c via IEC connector
Audio rail: + & - 18v monitored by the power LED
Phantom power: 48v dc switched from each channel with LED indicator
Introductory Price of the MT8016 2-Channel preamp $995.00 USD
Cheers, Dave
aamicrophones.com
PS. I will be adding some sound files to this Thread over the next couple of weeks of our MT8016 with a TLM103 on different source material. We will also have some feedback from Joseph Magee who used the prototype on Pitch Perfect III vocals. Also, European Engineer of the Year, Wes Maube has been using it on sessions at RAK in London and is currently writing a review on the MT8016.
We got this quick note from Wes recently.
"Spent an amazing weekend at RAK recording vocals and harmonica through the pre.
Wow, love it! And the artist was blown away.
Going to write the review in the next couple of days."
After several conversations over the years with console designers like our old friend Malcolm Toft who designed the Trident consoles and Tom Graefe who designed consoles for MCI/Sony as well as preamps for Wunder Audio...we came to the conclusion that we liked Malcolm, Tom and the Neve approach that relied on high quality input transformers which do not require a pre-transformer PAD.
Malcolm, Tom and myself all agree that using a PAD in front of the input transformer is frowned upon and can “suck the life out of a preamp”.
I owned and serviced two Trident Series 80B consoles in the 80’s plus a Neve console with 1073 modules.
I am very familiar with their sound and design.
Joseph Magee who is a client of Advanced Audio plus the supervising music mixer at Sony Pictures and the Pitch Perfect movies asked if we could build him a preamp based on the Series 80b console that he cut his teeth on in the 80’s.
Joseph told us he was never able to find a modern replication of the original Series 80b preamp that would give him the “British” sound that he remembered.
I also have never heard any reproductions of the original Series 80b modules that actually captured the original sound like those I used in my years at Ocean Sound in Vancouver.
Our good friend Malcolm Toft along with Chris Potter of Trident Studios were the original designers of the Trident Series 80b plus the A & B range consoles.
I have known Malcolm since 1979 when we bought the first Series 80b at Ocean Sound directly from Trident in the UK.
Malcolm and Chris customized it for our requirements plus we came up with a method to implement Hi/Lo "Q" on the sweep EQ's of the two Series 80b consoles at Ocean.
I also met Malcolm several times over the years at AES conventions where he was showing his latest designs and products.
Malcolm was more than excited to collaborate on the MT8016 design as he felt his considerable contributions to the Pro Audio Industry were being under utilized after he was commissioned to built the ATB Toft series mixer under a stripped down budget. Malcolm not only designed World Class mixers in the 70’s but as an engineer he recorded Hey Jude, David Bowies Space Oddity and James Taylor’s first album.
It was a huge privilege and honour for me to work with Malcolm on the design of the MT8016 preamplifier. Malcolm and I traded schematics and ideas back and forth for just over two weeks before coming up with the initial design implementation. We started in early April of 2016 and Malcolm delivered me the first production model for the Nashville Summer Namm show in late June 2016.
It took us from July 2016 until early December 2016 to fine tune the MT8016 and get the circuit boards and metalwork built in Canada. We can now hand assemble 10 units a month here in our shop.
We are expanding the production facility to be able to produce 20 preamps a month by the end of 2017. At this time we are custom assembling about 25 microphones a month and with the new "T" series tube microphone expect to be custom assembling 40 microphones a month by the end of 2017.
The Trident Series 80b had one of the first transformer coupled IC input stage microphone preamplifiers that we really liked and compared favourably to the Neve 1073. How, Malcolm and Chris accomplished this was by designing two independent op amp gain stages controlled by a dual pot. This clever design increases the headroom and transparency as the two stage work in tandem with each other.
Like the Series 80 and 1073 design the MT8016 has two gain stages controlled by a dual gain element. The Neve design switches in the 2nd gain stage after the 50db position while in the MT8016 the gain of each stage is brought up together optimizing the headroom and signal to noise. Each "op amp" stage in the MT8016 has 30db of maximum gain and the input transformer provides >15db of voltage gain with an overall gain of nearly 75db. The MT8016 gain pot also attenuated the output of the microphone transformer, -10db before the gain stages are activated at the 0db gain position.
Microphone signals from high SPL sources are attenuated after the transformer as indicated by the -10db setting at the start of the gain pot.
Our end goal was to design a "State of the Art” fully transformer coupled preamp with high quality parts for very affordable prices with a vintage look and feel.
Malcolm sourced the input and output transformers for the MT8016 from the same UK Company, OEP that provides transformers for Neve and wound the original Series 80b transformers. The input transformer that Malcolm spec'd had the same ratio and are true to the original 80b specifications but we had the transformers casing changed to be made PC mountable.
The 6:1 ratio input transformer gives us the sound from the MT8016 that we were looking for along with nearly 15db of voltage gain.
When a preamp design has no input pad the “sound” of the input transformer is more audible and “colours” the sound in a really musical way.
The MT8016 has a big transformer sound with great definition.
We were also thrilled to hear the series 80b preamp design with more modern components. We found that we could accomplish this and use electronic components that had better specifications than parts available in the late 70’s. The MT8016 uses OP275 IC’s in the audio path, this IC has twice the slew rate of the original TL071 and the OP275 can drive 600 ohm loads.
The original TLO71 started to suffer with loads great than 5K ohms as Malcolm buffered the output stage in the original Series 80b design with a pair of transistors.
With the OP275 this buffer stage is not required. The front end of the MT8016 circuit has been married to a transformer balanced output stage that further emulates the 70’s British console sound.
I also added a variable HP filter that I have found invaluable in my MCI/Sony MXP3036 that our good friend Tom Graefe designed.
In our experience a variable HP filter is usually all you need to clear up a muddy guitar and reduce pops and thumps without it effecting the vocal warmth.
The MT8016 has high quality toggle switches for phase, phantom power and HP filter engage. All switch positions have status LED's that light when activated. You have immediate visual indication that the phase switch or 48v power or HP filter circuit have been engaged.
The MT8016 also features a large analogue VU meter and a Peak LED above the gain control.
Measured specifications of the MT8016:-
Noise:
E.I.N. < -129dbm 20hz to 20khz input terminated into a 1K load
Maximum output:
+21dbm / +24dbu
Distortion:
1Khz +21dbm: 0.009%
40Hz +21dbm 0.5%
50Hz +21dbm 0.05%
Frequency response:
22Hz to 40kHz +/- 1db.
Gain range: -10 to +60db.
HP filter: 18db/octave variable from 30hz to 350hz
Power supply: 90v a/c to 240v a/c via IEC connector
Audio rail: + & - 18v monitored by the power LED
Phantom power: 48v dc switched from each channel with LED indicator
Introductory Price of the MT8016 2-Channel preamp $995.00 USD
Cheers, Dave
aamicrophones.com
PS. I will be adding some sound files to this Thread over the next couple of weeks of our MT8016 with a TLM103 on different source material. We will also have some feedback from Joseph Magee who used the prototype on Pitch Perfect III vocals. Also, European Engineer of the Year, Wes Maube has been using it on sessions at RAK in London and is currently writing a review on the MT8016.
We got this quick note from Wes recently.
"Spent an amazing weekend at RAK recording vocals and harmonica through the pre.
Wow, love it! And the artist was blown away.
Going to write the review in the next couple of days."
