Anyone tried the Golden Age Project PRE-73?

[joni0001984]

No, but I read an article saying it was no Neve, just not the same characteristics, but its a fairly good preamp. Sry to disappoint.

[lerone]

Originally Posted by AON

I got mail from Bo at Golden age music. He wrote that the PRE-73 is going to be availiable in august and that they will release the PREQ-73, or the PRE1-81 soon after.

Should be getting the pre 73 at the end of april. Im going to replace the trannies with cinemag ones. The cinemags are ALOT better than the carnhill ones in the actual neve 1073. So for about £300 and a few hours of legwork, the pre will be a bargain to say the bloody least. Can't wait to use it with some ribbons!!! Will definitely be looking into the Preq 73 and the 81 too. Bet some cheap simple mods could shoot them up into the true high end bracket too, at least sonically any how.


Toby

[B-sharp]

Ierone, that sounds very interesting. Living in the U.S. the Cinemags are also much easier to procure. Which transformer models are you using with the GAP? Please keep me updated what tinkering is needed to install, how they sound (still somewhat neveish, etc.)
Thanks

[andrewcolosimo]

I ordered the first one, after 20 days it no longer turned on. Due to constraints with return policy I didn't open it to check the fuse and returned it for another one. Same exact problem. Box came with one replacement fuse. I opened it up and it is blowing fuses. What can I do to resolve this? I am extremely happy with this device other than the fuse issue.

Andrew

[Syngriner]

Hey Andrew - The deal is that they shipped out the units with too small a fuse. If I remember correctly they came with a 1 amp fuse and actually need a 1.5 amp fuse. I think there is a mention of this in this thread. Get the right size fuse and everything will be fine.

[rty5150]

Originally Posted by lerone

Should be getting the pre 73 at the end of april. Im going to replace the trannies with cinemag ones. The cinemags are ALOT better than the carnhill ones in the actual neve 1073. So for about £300 and a few hours of legwork, the pre will be a bargain to say the bloody least. Can't wait to use it with some ribbons!!! Will definitely be looking into the Preq 73 and the 81 too. Bet some cheap simple mods could shoot them up into the true high end bracket too, at least sonically any how.


Toby

any update?

[yesac81]

Originally Posted by andrewcolosimo

I ordered the first one, after 20 days it no longer turned on. Due to constraints with return policy I didn't open it to check the fuse and returned it for another one. Same exact problem. Box came with one replacement fuse. I opened it up and it is blowing fuses. What can I do to resolve this? I am extremely happy with this device other than the fuse issue.

Andrew

hi andrew

the last batch of pre's shipped with fast blow instead of slow blow fuses, and they were too small (1 amp instead of 1.5 amps). the power on surge was tripping the fast blow. common problem with most of the pre-73's in the last production run.

cheers
casey
ebay: tallpoppydistro

[Audio Enginerd]

When I listened to the a/b/c comparisons on the ZenPro site I thought that the golden age pre73 sounded a little closer to the neve sound than the cham labs 7602 did unmodded, and my 7602s get a lot of work around here. The 7602 sounds slightly cleaner sounding than the other two preamps to me. I personally didn't like what the mod did to the 7602. It sounded less smooth to me, but the pre73 took the mod better to my ears and personal preference. Listening again... I think what I'm hearing that I don't like is just the accentuating of the part of the test subjects voice that I don't like. It's kind of gritty. The differences between these preamps aren't huge. Especially with the clones modded.

[Oli_W]

I've been really enjoying my Pre73 - I'm using it with an SM7b for a rock/jazz album and both the singer and I adore the sound!

[drtaudio]

Hi Guys, I received my GA73 about a week ago.

Since I have serviced several Neve 1073 modules and Neve consoles I was excited to open up the GA73 and have a look inside.

What I saw impressed me and I am sure it would also impress Rupert Neve himself with how closely the circuit follows the original 1073 drawings that I have from 1973.

It also sounded really good out of the box and you would have to get up toward nearly $1200 a channel to get something that compares in sound and features I think.

The only difference I noticed right off was that the GA73 used electrolytic coupling capacitors where Neve used tantalums but this would only increase the price about $15. The tantalums are a little more accurate and generally considered more “HiFi” than electrolytic capacitors.

The heart of the Neve 1073 and a good part of the sound is derived from the 23 position gain switch which varies in 5db steps from -20db to -80db. This switch just like the Neve has 3 sections that are controlled together. The first section, adds 5db of attenuation to the -20/-25 and -30 positions after the mic transformer but before the first gain stage. The second section increases the first gain stage in 5db steps of up to -50db. Next the 3rd section is engaged after the OFF position and the second stage’s gain is increased from -55 to -80db. This elegant gain staging maximizes the signal to noise and minimizes distortion.

This is the part of the circuit where other Neve clones usually fall short and use a pot and often a single gain stage yielding 65db of gain max. The repeatability of the input gain settings in 5db steps is a marvelous feature when doing dialogue replacement and going from a “whisper to a scream” and back again.

However, the GA73 follows this complex dual gain staging circuitry to the letter.

Because there is no pre-transformer attenuation like API, the Tridents “A” range, “B” range, WBS M460/M470 and other discrete preamps from the 70’s. The “sound” of the transformer is more prominent in the Neve “sound” especially from high SPL sources that drive in the input transformer hard. A kick drum or snare drum can produce -10dbu at the input to the mic transformer on peaks.

I have included a picture of the stock GA73 transformer on the left, the Neve/St Ives in the middle and the Neve/St Ives with the case removed on the right. The next two pictures compare the stock GA73 transformer laminations to the Neve/St Ives laminations. When I measure the ratio of the stock transformer I get 1:2 in Hi Z and 1:4 in Low Z. I also noticed the stock mic transformer was more susceptible to hum and noise interference than the St Ives. The Neve /St Ives VT22670 has a ratio of 1:2.75 in Hi and 1:5.25 in Lo and the bi-metal laminations are much more sophisticated that the stock transformer which the pictures will verify.

I concluded that changing the input transformer would make the biggest “improvement” to the sound signature. When I replaced the stock transformer with the VT22670 I noticed an extended clarity in the low end and in the lower midrange as this area seemed to punched through more like the Neve. It was really evident on high level signals reaching the input transformer as the bigger transformer with its more sophisticated bi-metal laminations was able to handle the transients and low end better.

Tom at Cinemag makes an excellent shielded mic transformer for under $50 that would work well in the GA73 and be able to handle the full output level of microphones without any attenuation. It was a bit of a squeeze to fit in the VT2260 and the Cinemag is slightly smaller.

The output circuit feeds 24 dc through the windings of the output transformer to the 2N3055 output transistor configured in a class “A” circuit. Because class “A” output stages are not very efficient this transistor like in the Neve is mounted on a serious heat shink. Feeding the power supply through the output transformer causes it to slowly “choke” a bit on very large transients when the output level is high. This is another part of the Neve sound. This output transformer has a ratio of 1:2 so it increases the output level 6db giving Neve its enviable headroom. I am not sure if replacing this output transformer will make a noticeable difference to sound. The output transformer in my experience would not be a critical to the sound than the input transformer. If any difference could be perceived it would be at very high SPL levels that would cause any A/D converter to sound horribly distorted. The best of the A/D converters can only handle and input level of +23dbu before clipping distortion. This transformer is a bit smaller than the original in a Neve but no smaller than those used in a API or MCI back in the discrete transformer coupled era.

Cheers, Dave Thomas
Advanced Audio Microphones

GA73-Neve/St Ive-Neve/St Ive ...GA73 transformer laminations ..... Neve/St Ives laminations...........GA73 w/new knobs & vt22670

[kidvybes]

Originally Posted by drtaudio

I concluded that changing the input transformer would make the biggest “improvement” to the sound signature. When I replaced the stock transformer with the VT22670 I noticed an extended clarity in the low end and in the lower midrange as this area seemed to punched through more like the Neve. It was really evident on high level signals reaching the input transformer as the bigger transformer with its more sophisticated bi-metal laminations was able to handle the transients and low end better.

Tom at Cinemag makes an excellent shielded mic transformer for under $50 that would work well in the GA73 and be able to handle the full output level of microphones without any attenuation. It was a bit of a squeeze to fit in the VT2260 and the Cinemag is slightly smaller.

Dave...your findings in regard to the mic input transformer being the most beneficial upgrade for the PRE-73 are the same as my Neve tech who has vast experience rebuilding vintage units as well as designing his own line of "iron in, iron out" preamps and summing boards...
...would you consider doing these upgrades as you have done in the past with the Chinese tube mics?...just curious...and thanks for your excellent post...very informative...

[RTR]

My PRE-73 should be here Monday!! I sure hope I like it..I sold my mpa gold to help fund this!!! By the way..who on here would be so kind as to replace the Input transformer for me..and how much $ will it cost for the part and you labor!!

[SWAN808]

anybody strapped 2 of these over the mix buss? If so how does it sound?

Would it be difficult to match the levels - and does it take line input...?

cheers

[drtaudio]

Hi, it depends which of the Chinese tube microphones you are referring to.

In the GA73 the Mic input transformer is important as it is getting "slammed" by the full output of the microphone and condenser microphones have a very fast transient response and a higher output level than a dynamic. Once the microphone signal reaches the first amplifier section its level can be controlled but the input transformer must handle anything that is thrown at it.

In the HST11a/APEX 460/NADY TCM1050/TCM1150 Chinese type tube microphones for example the wrong tube is installed. The circuit is basically a copy of the ELAM251 head circuit which was designed around a 6072 which has less than half the gain of the 12AX7 common in most of these microphones.

Also, these microphones generally come with a 32mm/3micron capsule which has its primary bump in the 3-4khz range.

Once you change the capsule, tube and modify the circuit then you can address the output transformer. The custom wound dual bobbin transformers that we use can handle 6db more level than the stock single winding chinese transformers. Also, you can reduce the turns ratio increasing the output and headroom.

We have a very nice dual bobbin transformer that has bi-metal lamination that we sell for about $45. It will yield 4db more output than the stock transformer but we reduce the gain of the input stage to take advantage of the extra transformer output which increases the headroom.

The Trion 8000 and a couple of the other bottle microphonea use a 7 pin Chinese 6J1 and we install a bigger socket and change this to a 6072 when we upgrade them. We again change the ratio of the transformer to increase headroom and lower the noise floor of the microphone.

Also, it is important to check the power supply voltage in the Chinese microphones as we find these can be a bit high and the capsule polarization voltage can as a result also be a bit high.

Cheers, Dave
Advanced Audio Microphones

[drtaudio]

Hi Guys, I will probably be upgrading the GA73 at some point. I haven't priced any transformers but I have put an order in for some tantalum capacitors.

I only have a couple of the original Neve input transformers left and they are a really tight squeeze. The Carnhils might be a couple of mm smaller. Does anyone know what the Carnhill sells for?

There are a couple of Cinemag option but you would loose the hi/lo impedance feature.

A Jensen JT-13K7-A will also work but it also has a fixed input impedance.

The Cinemag CMMI-3.5C or the CMMI-5C would probably work.

Cheers, Dave

Originally Posted by kidvybes

Dave...your findings in regard to the mic input transformer being the most beneficial upgrade for the PRE-73 are the same as my Neve tech who has vast experience rebuilding vintage units as well as designing his own line of "iron in, iron out" preamps and summing boards...
...would you consider doing these upgrades as you have done in the past with the Chinese tube mics?...just curious...and thanks for your excellent post...very informative...

[drtaudio]

You could use them as "real" Neve 1272 like buss/summing amps.

The GA73 does have a line input but the Neve 1272 was basically the output circuit of the 1073 with a Mic input transformer as the buss/summing input.

If you go into the mic input transformer and turn the gain all the way down then you basically would have a Neve summing amp.

Cheers, Dave



Would it be difficult to match the levels - and does it take line input...?

cheers [/QUOTE]

[kidvybes]

Originally Posted by drtaudio

Hi Guys, I will probably be upgrading the GA73 at some point. I haven't priced any transformers but I have put an order in for some tantalum capacitors.

I only have a couple of the original Neve input transformers left and they are a really tight squeeze. The Carnhils might be a couple of mm smaller. Does anyone know what the Carnhill sells for?

Cheers, Dave

Dave...I am told the correct Carnhill replacement for the mic input transformer is the VTB9045...it can be purchased from Audio Maintenance directly (about $65 US plus shipping)...link is here:
Audio Maintenance Limited Transformers and Inductors

...more cross reference info is provided here:
transformer cross table

...the VTB1148 is the narrow board version of the output transformer...

[warhead]

Originally Posted by Audio Enginerd

When I listened to the a/b/c comparisons on the ZenPro site...

I find the acoustic guitar files (24 bit) to be very revealing regarding tone and also low end response.

War

[theBackwardsman]

Originally Posted by drtaudio

You could use them as "real" Neve 1272 like buss/summing amps.

The GA73 does have a line input but the Neve 1272 was basically the output circuit of the 1073 with a Mic input transformer as the buss/summing input.

If you go into the mic input transformer and turn the gain all the way down then you basically would have a Neve summing amp.

Cheers, Dave



Would it be difficult to match the levels - and does it take line input...?

cheers

Cool, could you explain how to do this step by step?
Just got myself a pre73 and it would be nice to run a few mixes through it
I just dont get how to do it in stereo?

[Blast9]

Originally Posted by the Backwardsman

Cool, could you explain how to do this step by step?
Just got myself a pre73 and it would be nice to run a few mixes through it
I just dont get how to do it in stereo?

You'd need 2 units to do that!

[theBackwardsman]

Ok!

[mahasandi]

has anyone swapped out the stock input x former with 9045 mentioned above?

[asndy82]

Are there any other compatible mic input transformers that could replace the stock one and be a good fit in the space available? I am thinking could a OEP A262A3E work? Or maybe a Cinemag CMMI-8-PCA, or a Lundhal LL1538?

[Blast9]

Maybe look into Sowter?

FYI There's a comparison of input xformers here:

Neve transformer info

I guess there's also info re output xformers too

[gakmuzak]

Hi all. Just got my GAP Pre 73 yesterday. Ran it thru some basics to make sure each section/buttons worked etc. Now pls be gentle with me. I have some finished mixes (that were recorded in Sonar and mixed/psuedo mastered ITB) and have them exported as RIFF .wav files. I also use an Aardvark Q10 as my audio interface. My Q: Can I route the finished .wav file to come out of one of my Q-10's outputs in back, go into the GAP Pre 73 and then out of the GAP Pre 73 and into one of the front inputs of the Q10?? I would then open a new project in Sonar, and record that track "as is" with just the coloring of the GAP to warm it up. Can I do this with just the one unit?? Or would I have to get a "y" cable and take two outputs from the Q10 (eg: L,R mix with Out 1= Left, Out 2=Right) and then sum them together to go into the GAP Pre 73. I think I can, but wanted opinions first. FYI, I do know that my routing options on the Q10 do not allow a L/R combined to come out of one output, so my main concern is combining that signal to go into 1 GAP Pre 73 to use as a "color"?? Whew....think I said all this right. Your answers are greatly appreciated.

[Blast9]

You'd need 2 GAP Pres to do that with a stereo master, as they are mono units thumbsup

perhaps try the "colour thing" in the box - there's many great plugins that will give you a wide palatte of colour/distortion

[gakmuzak]

Hi Blast9 and thanks. I posted this same ? on the other forum and was told that I could indeed do it. I would just have to take the "Monitor L" signal from one of the outputs (in this case output #1) on the Q10 and then run that through the GAP Pre 73 and into one of the inputs on the front of the Q10. I would then arm a trk in Sonar and record just the left channel info. I would then take the "Monitor R" signal (again from the same output-#1 in the Q10-fyi the outs on the Q10 are all software routed), go throught the GAP PRe 73, into an input on the Q10 and then arm a second trk in Sonar and record the right channel info. Then I would have the two trks in Sonar colored with the GAP Pre 73 almost like using a Neve as a summing pre; pan trk 1 hard left, trk 2 hard right and then export that as a new stereo 2 trk. As long as I start the recording at the same place, there shouldn't be any phase/timing issues (at least that's what some of the posters on GS told me on the other forum). Think this will work?? I will eventually get a 2nd GAP Pre 73, but for now, one will have to do.

[Blast9]

Oh yeah - that shoud work as the "round trip" latency will be the same in each channel thumbsup

[lucianop]

My GAP 73 arrived today. Very happy with it.
In my first test I switched from my presonus firebox mic preamp to gap73 and I was shocked by the difference. Like someone turned on the light in my dark room.
In a few words I felt a sort of transition from "prosumer" to "professional".
Tested on vocals(great), bass(very good), entire mix (added a sort of +5% in quality).
Just planned to buy a second one.

[Matti]

Originally Posted by lucianop

My GAP 73 arrived today. Very happy with it.
In my first test I switched from my presonus firebox mic preamp to gap73 and I was shocked by the difference. Like someone turned on the light in my dark room.
In a few words I felt a sort of transition from "prosumer" to "professional".
Tested on vocals(great), bass(very good), entire mix (added a sort of +5% in quality).
Just planned to buy a second one.

And the compressors to match them

Matti