What Ics to use on a Neve V series ?
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musgrave
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and Bobby" heat mod to keep modules cooler...
nielsk
Well-known member
An understanding of DC offset and how it can be dealt with is helpful when one desires to eliminate DC blocking capacitors from an audio path.
We have smart thermostats and warning lights in our machine rooms. The smart thermostats email the manager if temp or humidity exceed a threshold and the warning lights notify staff of extreme conditions. We’ve had condensation issues, too, so now we keep small dehumidifiers running in our machine rooms. Our big machine room has a traditional hvac system plus a smaller split system as a backup.
These rooms were built with big budgets in the late 90s, when consoles cost what a Malibu tear down goes for today, so the cooling systems were a small percentage of the desk and integration costs. Used large format consoles are relative inexpensive today, but the infrastructure still needs to be there. It’s only time and money….
living sounds
Well-known member
I wouldn't even change 5532/5534 chips to a different brand or different production date needlessly. This console was designed with exactly the chips used in mind, making changes is asking for trouble. I've been there too many times... Don't change normal electrolytics for low ESR either, same thing. Don't just add any decoupling caps anywhere or change the size of PSU decoupling caps, again, potential trouble. With a system this complex you can search forever for the problem you inserted...
pucho812
Well-known member
I concur. Ams/neve designed around the 5532/34, it’s a known solid chip. No need to change it. Plus most changes are not as noticeable until you hit distortion land. Or on some cases cause oscillations and other unwanted issues.
As for complexity yes, they are. Another tech I worked with got into the habit of working on the desks with the power on. Usually not a big deal as you can hot plug a module. Not a best idea but it can be done. Anyway while working the aux master module he managed to short it out when putting in back in. We lost ever aux master. After going over schematics and the board. I found the first best start to what went, a fuse. It was on the schematic. Took a day to find it as it was physically located no where near the aux masters.
Musgrave, I send you my email via Pm.
About the temperature of the console I started by milling the back frame of the channel. The goal is to add 3x140mm ultra silent fans that will suck in hot air out of the bucket. I got some help from Michele Signorini that did this mod on his board. You can find picture on his Facebook profil.
I’m waiting for fans to arrived then I will make temperature test with and without fan.
About 5532 on the channel. I will try to mods one of the extra channel with Opa1662 and make sound measurements, electronics consumption of the channel and how it heat.
About the temperature of the console I started by milling the back frame of the channel. The goal is to add 3x140mm ultra silent fans that will suck in hot air out of the bucket. I got some help from Michele Signorini that did this mod on his board. You can find picture on his Facebook profil.
I’m waiting for fans to arrived then I will make temperature test with and without fan.
About 5532 on the channel. I will try to mods one of the extra channel with Opa1662 and make sound measurements, electronics consumption of the channel and how it heat.
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musgrave
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For the heat mod that’s exactly it. Bobby went on to make sheet metal ducting and 6 inch pipes down into the floor to the return of his air conditioning and this sucked in the cold air from the room and send it through the AC. I am using the OPA 2134, OPA 134 and following the Mike transformer and VCAOPA228 because they clip very nicely, and don’t latch up just a perfect square. They’re gonna pull a little bit more current, then run a tad hotter, but with the cooling mod you should be cool. as far as coupling caps go, you’re pretty much stuck with them, but there’s two jumpers that you can add to drop the noise floor by a factor of 100. It’ll be in all in the information I send. Robin Porter and I worked out the micpre in my shop back in the 90s. It’s the same thing as the 88 R micpre-upgrade. I tuned mine a little more gentle than Robin tuned his. Then in the EQ I put OPA 2134 or in general just fet amps in all but IC11 of the EQ makes up huge difference. The Micpre, the jumpers and the EQ give you a lot of bang for your buck. I picked the OPA 2134 because they sound great and they have always been stable. I modified well over 3000 modules, they go all over the world and stability is king.
musgrave
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The small DC offsets are going to keep adding up and adding up. We went through and replaced all the caps with jumper wires just about one at a time and it was just undoable like is mentioned above. I think it’s C 22 or C 24 in the input section is the only cap we got rid of and that’s on the information I’m going to send you. I use the 2134s because they’re internally compensated and using faster more popular ones I had complaints of random oscillations, depending on whether and humidity. I’m not the most technical guy, my philosophy is that we are making stories and tracks that fit together well and make a great story, this is what I’m after. but I do put in a lot of effort in seeing what works and what doesn’t work. with the two jumpers on the grounding that improves the noise floor we spent two days, adding and removing jumpers to see who made the differences. This came about having one ground missing and jumping it to another ground and being totally amazed at the difference in the noise floor.
musgrave
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Been there and done it… then the fuse cap pops out and falls into the wiring in the trough. No one can find it and now someone has to drive to the electronic store or steal one out of another piece of gear to keep the session running… haha
all my best, and thanks for the shout out
ruffrecords
Well-known member
My good friend Clive Angel worked on the mechanical design of the Neve V series. I have contacted Clive and asked him what he remembers about the heat problems. Clive is in his 80s now and the V series was designed 40 years ago. He has told me what he remembers. I am just waiting for his permission to copy it here.
Cheers
Ian
Cheers
Ian
ruffrecords
Well-known member
Clive got back to me. Here is his email about the V series heat problem:
Ian
Cheers
I think I i'm right in thinking that the V series was the first digital desk Neve ventured into.
And the one that the heat generated by all the ( CHIPS ) EMPLOYED took everybody involved by surprise. !
I Remember that a chap called Andy.! did some calculations and found the power consumed by the desk. was over 1.4 kwatts
Now ! without the use of forced ventilation. No ( Fans ) allowed in the studio. Getting rid of the heat was a nightmare. .
I had to go back to basics, HEAT always rises. !!!
Hence the under tray of the console was cut out replaced by open mesh. The under desk trunk with all the module connections are . had the rear panels ventilation holes . added.
Top back of console had large vent slots added. That still didn't give enough cooling. !
Leaning over the console i realised the heat was all coming from the individual modules. and due to the angle of the modules it could not get away. ( Way to hot to touch. ! )
Hence i had to get the surface heat away. !
That's why all the pots. ! have a moulded ventilated support mtg. under the knobs. Holding the knob up by 2 mm to leave an air gap.
and the faders are spaced off top section by 5 mm and the fader slot in the panel is 5mm wide. leaving air gap. and therefore needed extra long knob mtg. shaft. allowing air to get up.
After many nights of trying different fixs ( development was over mid summer and days were very warm. so coolest temps over night., ) LARGE multi channel temp. recorder all connected up. !
So it was all near the bone stuff.
The cables from modules back to main bus bars were found to have better air flow over them. by not being t fixed back to a big mtg channel. ( plus it improved cross talk. immensely. )
Be interested to know how many of the V series desk are still in operation. ?
Hope this helps.
Catch up later
cheers
Clive
Ian
quick question - What is a "mtg channel" ?
Walrus
Well-known member
The two 72 channel Neves that were at Whitfield Street/Sony Music studios were obviously very early models, as none of the back panels had the cutouts. And yes, they got very hot!
Matt Syson
Well-known member
The first version AMEK RN Mozart channels got so hot that the circuit boards went black but I and others found ways to reduce the heat build up for later issues; The name Neve seems to be the common factor with equipment that gets too hot! Greater use of MC33078 replacing NE5532 was a big help as their standing current is around half of the NE chips but still perform well for analogue duties. Later desk designs had better airflow built in and the 9098 had specific channels (ducting) to direct airflow.
Over the decades I have used truckloads of Bifet TL07x. In my experience properly applied (modest gain and lightly loaded) these op amps are transparent to line level audio.
JR
living sounds
Well-known member
In a similar vein, my ADT console makes use of plenty of RC4558 op amps. Replacing those with 5532 oder better doesn't do anything useful but increases current draw. Thanks to thoughtful use of op amps this large format console gets only warm but never hot and works with a passively cooled external PSU.
pucho812
Well-known member
Always wanted to test drive an adt desk. Sadly I do not know of any on this side of the world.
I haven't shared this lately, but back when I was writing my "Audio Mythology" magazine column I did a comparison of +4dBu and -10dBV nominal 0VU systems. The ASSumption would be that the +4 dBu system with a few dB hotter 0VU should have superior performance all around. That was not the case looking at objective metrics. The S/N was limited by the ein of electronic parts available back in the 1980s, so likely even better today using modern op amps. Surprisingly back then the -10dBV systems could deliver slightly better headroom/dynamic range.
A lot of the -10dBV gear used relatively slow op amps, but did not slew limit under normal use because the nominal signal levels were also smaller.
As with any design its all about execution.
JR
A lot of the -10dBV gear used relatively slow op amps, but did not slew limit under normal use because the nominal signal levels were also smaller.
As with any design its all about execution.
JR
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