Sorry about that - the unsubstianted claims just looked exactly like marketing for the uninformed masses
Recommendations on how I can learn to build a Sony C800G clone
- Thread starter Deadrecords
- Start date
Help Support GroupDIY Audio Forum:
electronaut
Well-known member
So far, the only unsubstantiated claim with regard to my project has come from you, Jakob. You could have asked me how it came to be that we chose the C800g, rather than declaring your unsubstantiated theory.
The truth is, I had nothing to do with the choice of the microphone. It was my idea to design a preamp around a specific mic, and it was my client who chose the mic, so your theory of greedy capitalist intent to “cash in” on the “uninformed masses” falls flat. It also makes you look cynical and petty.
The members of this community should expect better from a “moderator”.
My IP address has now been banned with no reason given, so I’m posting this from my phone. If you don’t see me posting in the future, that’s why.
Take care, everyone.
Last edited:
Hi Rob,
Sorry to see that a GDIY member’s intentions were misconstrued.
Yes, we might be a bunch of cynical ageing men (majority clearly are male).
But I must admit that I’m also sceptical as to why your pre-amp would be that much better for a Sony C800G than let’s say a Neve 1081 or an Avalon or an SSL E solid state pre-amp?
And yes, why choosing a C800G?
PS: OP was about how to learn to build a Sony C800G. We’re drifting. I’m also posting from my phone
M
Last edited:
electronaut
Well-known member
You could ask the same question about any other mic/preamp combo: why should preamp A be any better than preamp B or preamp C?
The client was already using a Neve Shelford with his C800g and was getting great results. He was interested in adding a tube preamp to expand his options, so I designed one for him, and rather than build a general-purpose high-gain preamp with phantom power, polarity switch, pad, and/or other input options, we decided to strip that all away and focus solely on the requirements of the mic. As a result, the noise floor, frequency response, input loading, output drive capability, total system gain, and distortion characteristics were centered around the client’s mic and their typical workflow.
And yes, the mic happened to be a Sony C800g, but it could have been any mic. That’s just what the client asked for.
Given the option, I’d rather load the mic in accordance with the manufacturer’s recommendations than not do that. My preamp does that, their previous setup didn’t. Your skepticism about whether that makes any difference doesn’t carry more weight than Sony’s recommendations.
That’s an example of one of many small choices that were made to suit the requirements of the mic, some of which had surprising consequences and lead to surprising outcomes; i.e. choice of signal transformers, power supply design, etc.. It was a fun process, it turned out great, the client loves it, and it’s totally ok if you’re skeptical.
Why was my IP address banned?
The client was already using a Neve Shelford with his C800g and was getting great results. He was interested in adding a tube preamp to expand his options, so I designed one for him, and rather than build a general-purpose high-gain preamp with phantom power, polarity switch, pad, and/or other input options, we decided to strip that all away and focus solely on the requirements of the mic. As a result, the noise floor, frequency response, input loading, output drive capability, total system gain, and distortion characteristics were centered around the client’s mic and their typical workflow.
And yes, the mic happened to be a Sony C800g, but it could have been any mic. That’s just what the client asked for.
Given the option, I’d rather load the mic in accordance with the manufacturer’s recommendations than not do that. My preamp does that, their previous setup didn’t. Your skepticism about whether that makes any difference doesn’t carry more weight than Sony’s recommendations.
That’s an example of one of many small choices that were made to suit the requirements of the mic, some of which had surprising consequences and lead to surprising outcomes; i.e. choice of signal transformers, power supply design, etc.. It was a fun process, it turned out great, the client loves it, and it’s totally ok if you’re skeptical.
Why was my IP address banned?
Last edited:
Does the PSU contribute to the sound of the C800G?What surprises me is that the external C800g PSU is not worth a single word to the author.
I like the 0.22F caps in the heater voltage supply, too.
k brown
Well-known member
All audio devices are affected by the quality of their power supplies - their sound is literally the modulated power supply.
electronaut
Well-known member
As far as noise is concerned, it depends on the circuit topology and its ability to reject power-supply noise, expressed as power supply rejection ratio, or PSRR. In a grounded-grid amplifier, the PSRR can be approximated by the voltage divider formed by the load resistance and the anode resistance (PSRR = Load Resistance + Anode Resistance / Anode Resistance). In a cathode follower, it can be approximated by the inverse of the mu expressed in dB.
Last edited:
terry setter
Well-known member
- Joined
- Nov 17, 2013
- Messages
- 153
Probably more important than whether your PS uses a tube rectifier is that the Sony 800G heats the tube at 4.6VDC! Don't be thinking that you'll get a "better" sound if you raise that up to 6.3VDC. You'll get a DIFFERENT sound, and it won't sound like a Sony 800G.
That said, I built a mic supply using tube rectification and it worked really well (sounded very, very good and I was able to filter it down to be extremely quiet (greater than 106dB S/N). The tube was a 6X5.
That said, I built a mic supply using tube rectification and it worked really well (sounded very, very good and I was able to filter it down to be extremely quiet (greater than 106dB S/N). The tube was a 6X5.
Im guessing that the C800G will sound like a C800G if it had a non Sony PSU with the same specs?
I don't see why it wouldn't.
Then that is why I didn't include the PSU in my Gearspace post. From all of my research online, the biggest differences between the "clones" and the original C800G, is that none of them match what the actual mic has in order to sound like it. All the articles and interviews with the engineers that designed the C800G, that were translated from Japanese, talk mostly about what make the mic sound the way it does, and very little about the PSU. I don't see why I would include the PSU comparing the "clones", when they didn't even get the microphone itself right.
If I include the PSU, I might as well include the mic cable/shock mount/temperature of the ambient air/electric company/time of the day the electricity the electricity is purest/which part of the hemisphere you reside/atmospheric gravity
It's not a major factor in my opinion on why the C800G is a C800G. But I am no expert.
rock soderstrom
Tour de France
Remember, these are opinions and they vary. It would be interesting to do really reliable blind tests on this topic. The power supply of the C800g is a bit different from most others. Only a real test can show whether this leads to audible (and measurable) differences, but I wouldn't rule it out completely from the start!
I think there are differences between the effects of a real circuit and the stuff you're talking about here. The original article on gearslutz was very detailed, I think a closer look at the power supply would have fitted in well. If you equate that with the power quality of your energy supplier and the "time of the day the electricity is purest", I can't take you entirely seriously. Sorry.
Last edited:
It was in jest, it wasn't meant to be taken seriously.
I would've mentioned the PSU in my post, but there wasn't much information on it from the designers. So I just went with the microphone. Which is the major contributing factor of what makes the sound. If you find any information on the power supply, you can reply to the post and add the information. More information is always welcome.
Weeeeeell, i'd argue there's a pretty good chance the tube rectification for the B+ rail becomes virtually irrelevant with the 5.6k / 220uF / 8.2k / 220uF filtering in the power supply, and there's another 10uF on the B+ rail inside the mic.
Heater rail's filtered with 20mF (yes, milifarads), zener-regulated, plus 2200uF and an extra 2F with those supercapacitors.
https://elektrotanya.com/sony_ac-mc800g.pdf/download.html
Yeah, i'd call the power supply a non-issue...
rock soderstrom
Tour de France
The PSU schematic is available, however, and contains everything you need to know.
I don't post on gearslutz anymore.
But that's just your opinion from a distance, you haven't done a blind test on this topic yet, have you?
As you know, I can read schematics as well and I can see some peculiarities in the PSU of the C800g compared to many other tube microphones.
From my point of view it would be interesting to do some comparative measurements, if you a really interested. I'm talking about technical data first, and once you're through with that, as I said, blind tests would be helpful if you really want to get to the bottom of it. (This was the claim of the original GS thread).
Otherwise these are just opinions from a distance. Volume and frequency of repetition are no substitute for real data and experience.
It is quite possible that the differences are marginal and possibly not worth the effort. Nevertheless, I would not categorically rule it out, my experiences were partly different. Power supply topologies and dimensioning play a technically important role, to what extent the sound varies is something everyone has to work out for themselves.
I cannot look at a schematic and determine WHY the designers went the route they did. We are debating semantics at this point. My post was outlining the designers perspective, translated from their interviews. Hence, why I posted nothing on the PSU. This was my original reply to you. Like I said, im no expert...I just posted what I researched. If you have an issue with the perspective of what contributing factor the PSU has, then you should take that up with the designers...or maybe the original interviewer/article writer.
rock soderstrom
Tour de France
What the hell are you talking about? This isn't Gearslutz, we like to look at schematics of the things we're talking about, I don't need an "interview" from some "designer" to see what's going on. What kind of expertise is that when you take the marketing blah blah from some interview as the gold standard and base your statements on that? Have you ever built a microphone with a power supply? How many? Is it enough to read interviews with "designers" to be a player now?
That's GS style, we don't need that here. We like facts!
Last edited:
Please calm down. You asked why I didn't post about PSU in my gearspace post...I told you why I didn't. I couldn't find any insight on design choices by the designers. I think emotional tantrums on disagreements is what we don't need from "GS style" posts. If you have anything intellectual to contribute to the post, like a schematic or what you find on the PSU...then please post it. If not, then please lets move on like adults. I don't see the point in arguing about "why didn't you post __________?" When you can really be contributing to the conversation by posting what you see is missing.
rock soderstrom
Tour de France
So, is this a theroethical debate or are we talking about building an authentic (whatever that is) C800g microphone?
That's the thread title, just a reminder, this is not your thread.
Again, have you built a mic with a PSU yet?
If this is just meant to be a poetic description of this topic, GS is actually the better place for it in my opinion.
Open up a new thread, maybe it will run a bit better than the old one.
Similar threads
