tubedude
New member
http://www.seventhcirclestudios.com/N72/N72
Good prices, it seems... some discussion on these over on RAP right now.
Good prices, it seems... some discussion on these over on RAP right now.
crawdad
Dammit, Jim, Shut Up!
Thanks for posting this. I am interested in possibly building one in the future. What are they saying about it on RAP?
D
Dan Kennedy
New member
But you have a studio right? Why don't
you already own a good soldering iron,
dikes, needlenose, screwdrivers and solder and solderwick? Don't forget a
DMM.
If you don't, you should be ashamed.
Now it's not nearly so expensive, and it
looks like a nice project.
Don't forget chassis and power supply
in your budget.
you already own a good soldering iron,
dikes, needlenose, screwdrivers and solder and solderwick? Don't forget a
DMM.
If you don't, you should be ashamed.
Now it's not nearly so expensive, and it
looks like a nice project.
Don't forget chassis and power supply
in your budget.
crawdad
Dammit, Jim, Shut Up!
Dan Kennedy said:
Dan--What would you estimate a power supply to cost for this module? For some reason, I was thinking that transformer was for power, but I'm not the sharpest knife in the drawer when it comes to electronics!
L
laaronx
New member
those xformers are all input/output. A pretty good power supply would probably be pretty cheap though because of the low current requirement. A nice toroidal transformer from avel-lindberg would probably run about $20 (recommended for low noise), maybe $10 for good rectifier diodes, another $10 for filtering caps, and maybe another $10 for some proto board to mount it on.
It doesn't look like that bad of a project. It's nice that all the pots and connectors are soldered right into the board, wiring pots and connectors and mounting in an enclosure always seems to take the longest time with stuff like this.
Thanks for the link!
It doesn't look like that bad of a project. It's nice that all the pots and connectors are soldered right into the board, wiring pots and connectors and mounting in an enclosure always seems to take the longest time with stuff like this.
Thanks for the link!
MISTERQCUE
Not Just Anutha Brutha
If one was to indeed build one, using required parts from,
say Radio Whack, can you still call it a NEVE pre even if you constructed it yourself!!??
say Radio Whack, can you still call it a NEVE pre even if you constructed it yourself!!??
crawdad
Dammit, Jim, Shut Up!
Thanks Laaronx! I appreciate the feedback.
D
dragnalus
New member
http://pub55.ezboard.com/ftapeopfrm2.showMessage?topicID=1098.topic here's a thread of the creator of this pre kit talking about it. in fact, i think he was finding out if there would be enough interest to even do it in the thread.
re: radio shack: uh, no. a lot of what makes a neve a neve is the use certain top shelf electronic components, which is not what radio shack is known for. you could follow the schematics with radio shack components but it wouldn't really be the same pre.
re: radio shack: uh, no. a lot of what makes a neve a neve is the use certain top shelf electronic components, which is not what radio shack is known for. you could follow the schematics with radio shack components but it wouldn't really be the same pre.
D
Dan Kennedy
New member
I'd up the supply estimate some, but not
too much.
I think you need at least a 6800uf/35 or 50 volt electrolytic for your main filter cap.
I agree with the 22 + 22 Avel as the transformer.
I wouldn't do this project without at least an LM317 style regulator. That'll add a couple of bucks with the right caps, diodes, resistors and heatsink.
Don't forget the stuff for phantom.
Don't even think Radio Shack, get thee online and learn the wonders of DigiKey.
too much.
I think you need at least a 6800uf/35 or 50 volt electrolytic for your main filter cap.
I agree with the 22 + 22 Avel as the transformer.
I wouldn't do this project without at least an LM317 style regulator. That'll add a couple of bucks with the right caps, diodes, resistors and heatsink.
Don't forget the stuff for phantom.
Don't even think Radio Shack, get thee online and learn the wonders of DigiKey.
H
h kuhn
New member
power supply
you might get away with the positive half of fred forsell's PS (http://www.forsselltech.com/ ) design using the LT1085. It is an adjustable Regulator with very good ripple rejection, up to 3A (i think the 1084 goes up to 5A). I have build another preamp with this PS and it works very well (using my ribbons at wide open gain I can't hear any difference to running the same unit with battery power). The only problem might be that the suggested smoothing caps won't fit in a 1U chassis, but you can use a couple of smaller caps in paralel. Digikey now carries toroid powertransformers (i am not shure if you can find them in their online catalog, I have seen them in their printetd catalog), and they sell some simple aluminium rack chassis for around 50$, too.
you might get away with the positive half of fred forsell's PS (http://www.forsselltech.com/ ) design using the LT1085. It is an adjustable Regulator with very good ripple rejection, up to 3A (i think the 1084 goes up to 5A). I have build another preamp with this PS and it works very well (using my ribbons at wide open gain I can't hear any difference to running the same unit with battery power). The only problem might be that the suggested smoothing caps won't fit in a 1U chassis, but you can use a couple of smaller caps in paralel. Digikey now carries toroid powertransformers (i am not shure if you can find them in their online catalog, I have seen them in their printetd catalog), and they sell some simple aluminium rack chassis for around 50$, too.
crawdad
Dammit, Jim, Shut Up!
Let me ask you guys a question. If I was making a kit, I would assume that people who would buy it were non engineers(electronics). Therefore, if I was making a mic pre kit, it would seem obvious to me to either offer a power supply kit or include it as part of the mic pre kit. To not offer one at all would be making the assumption that everybody who is building the mic pre has a good understanding of electronics and the math required to build a power supply from scratch.
Am I crazy to be let down by the fact that I have to try and figure out the power supply on my own? I am not trained in electronics, although I have built a power supply for some PAIA stuff and have built several of their kits and an entire tube amp. The difference was that I was given the parts and "how to" instructions, which I was able to follow easily.
So now I don't know what to do with this kit. On top of that, Dan has mentioned that I'll need to add phantom power to it as well. Well, I am so confused now that I'm kind of giving up on this kit. I'd like to make it but its a lot of money for something that is incomplete and I don't have time to get my degree in electronics. Damn!
Am I crazy to be let down by the fact that I have to try and figure out the power supply on my own? I am not trained in electronics, although I have built a power supply for some PAIA stuff and have built several of their kits and an entire tube amp. The difference was that I was given the parts and "how to" instructions, which I was able to follow easily.
So now I don't know what to do with this kit. On top of that, Dan has mentioned that I'll need to add phantom power to it as well. Well, I am so confused now that I'm kind of giving up on this kit. I'd like to make it but its a lot of money for something that is incomplete and I don't have time to get my degree in electronics. Damn!
H
h kuhn
New member
crawdad said:
Crawdad
I am by no means an electronic engineer either. But building a PSU for a mic pre is no rocket science. I have done it (and survived...) so why shouldn't you be able to do it?Just be *very* careful when wiring the primary of the powertransformer, I have opened up a couple of other PSUs before and studied how they are wired, and had my whole design double checked by an experienced engineer before I connected it the first time. there is also a couple of designs out there on the net.
Last not least you can go and buy a good regulated 24V power supply and an external unit for phantom power (I think rane sells one, audiotechnica too. Stay away from the Rolls/bellari...)
L
laaronx
New member
Just curious why you guys are in favor of PS regulation? From what I understand (not nearly as much as I probably should) regulators can constrain the current through the PS during sharp transients. I'd appreciate your views on the compromise.
re: power supply construction, I agree it should be a part of the kits, and there's really no reason why they couldn't have the components mounted right on the PCB; my guess is that because transformers are usually the most expensive electronic components, it would drive their margins down to include them. However, it is pretty easy to build one. There are very complicated designs that have voltage regulation, etc. but really all that's usually needed is a transformer, some rectifier diodes to convert the AC to DC, and some filter capacitors to smooth out the DC and store power. After you've done a simple one, you can always upgrade it later and see how it improves the gear.
re: power supply construction, I agree it should be a part of the kits, and there's really no reason why they couldn't have the components mounted right on the PCB; my guess is that because transformers are usually the most expensive electronic components, it would drive their margins down to include them. However, it is pretty easy to build one. There are very complicated designs that have voltage regulation, etc. but really all that's usually needed is a transformer, some rectifier diodes to convert the AC to DC, and some filter capacitors to smooth out the DC and store power. After you've done a simple one, you can always upgrade it later and see how it improves the gear.
tubedude
New member
Hey Dan Kennedy! Neat to see you around here.
For the longest time we were hunting around for a kit and someone with some know-how to lead a group of us through it one step at a time. I know it would consume some time, but would you be willing to do it? Actually, you could devise your own board and sell those and the parts or parts list and make some cash for yourself in the process. Or, we could just use something like the Neve circuit I posted above. This would be a good lesson for a lot of us, especially people like me that have never built anything similar. A digital camera would be nice in order to show step by step process. We could even offer a prize to the 1st person to burn thier house down
If you arent interested, is anyone else?
For the longest time we were hunting around for a kit and someone with some know-how to lead a group of us through it one step at a time. I know it would consume some time, but would you be willing to do it? Actually, you could devise your own board and sell those and the parts or parts list and make some cash for yourself in the process. Or, we could just use something like the Neve circuit I posted above. This would be a good lesson for a lot of us, especially people like me that have never built anything similar. A digital camera would be nice in order to show step by step process. We could even offer a prize to the 1st person to burn thier house down
If you arent interested, is anyone else?
T
trebles
New member
"Tubedude"
The Kit idea is always a good deal, if you can get numbers of people who want to buy this you can keep your price down.
You need a contact to be able to buy all the internals, pwr supplies, etc at trade price or below.
Then you need someone like an electronics student in their later years who is willing to make these kits up for a fair non commercial price. just someone who aint got their calculators out on your project and is willing to do good consistent work for a rate of pay or someother sweetner in the bargain.
Once you have your test unit finished. i guess it would be a good idea to have it certified as being a safe deal to plug in and be used by the mass.
at least the above option should be something strongly considered.
Now if you want to do this and its to assist others home reccers here, then the group of people who get involved in this need to know all the costs upfront, no one id say has a drama with the person handling the goods making some small amount to cover their costs, its just when it becomes a commercial venture thats when it becomes questionable,there are already people out there who could sell you a similar deal but at a shop front price.
now im not knocking an idea just saying that with that deal comes waranty, after sales service, and even unit replacment.
with a kit deal non of the above would apply so you see there is alot to be considered.
I reckon Dan Kennedy would be the best person to do such a job if we all were so lucky, but i am sure Dan also has to run his business so such a job like ours may not be a viable thing for him to do just my opionion.
he may feel completly different but that would be only something Dan can answer.
What id say is a great deal would be get together a large number of people to buy one of Dans products and then make it worth his while i am sure he would save us as a group a whole lot if we could get a group together to buy one of his mic pres just a thought.
The Kit idea is always a good deal, if you can get numbers of people who want to buy this you can keep your price down.
You need a contact to be able to buy all the internals, pwr supplies, etc at trade price or below.
Then you need someone like an electronics student in their later years who is willing to make these kits up for a fair non commercial price. just someone who aint got their calculators out on your project and is willing to do good consistent work for a rate of pay or someother sweetner in the bargain.
Once you have your test unit finished. i guess it would be a good idea to have it certified as being a safe deal to plug in and be used by the mass.
at least the above option should be something strongly considered.
Now if you want to do this and its to assist others home reccers here, then the group of people who get involved in this need to know all the costs upfront, no one id say has a drama with the person handling the goods making some small amount to cover their costs, its just when it becomes a commercial venture thats when it becomes questionable,there are already people out there who could sell you a similar deal but at a shop front price.
now im not knocking an idea just saying that with that deal comes waranty, after sales service, and even unit replacment.
with a kit deal non of the above would apply so you see there is alot to be considered.
I reckon Dan Kennedy would be the best person to do such a job if we all were so lucky, but i am sure Dan also has to run his business so such a job like ours may not be a viable thing for him to do just my opionion.
he may feel completly different but that would be only something Dan can answer.
What id say is a great deal would be get together a large number of people to buy one of Dans products and then make it worth his while i am sure he would save us as a group a whole lot if we could get a group together to buy one of his mic pres just a thought.
T
Tim Ryan
New member
Power Supplies, etc.
Hello all,
Well, this is pretty cool. I appreciate your interest in the N72 kits, and I'd be more than happy to answer any questions you might have about them, or talk you through any construction issues or concerns you might have. I've gotten good feedback from the few intrepid kitbuilders out there who have already jumped in with both feet, so I think building the kit will be a good experience for most who try it.
As for power supplies, if you have a look at the "Parts List" page there are two Power 1 linear supplies that will work fine with the N72. Neither use toroidal transformers, nor are the transformers shielded, so if you go that route you might want to consider installing them in a separate enclosure, a la the George Massenburg gear, among others. I'm currently working on a power supply design that will fit nicely into the 2U Bud enclosure I've used for my prototypes, but that won't be available for at least another month. For those that are interested in building their own, I suggest you go to http://www.national.com and get a datasheet for the LM317 regulator. It'll tell you just about everything you need to know.
BTW, the reason to use a regulated supply is that an active regulator reduces the output ripple by an order of magnitude or more over a simple RC filter, is much less expensive than using big inductive chokes, and allows the use of smaller filter caps than you'd otherwise have to use. It's true that for some applications an LM317 type regulator might not be optimal, since they do have a finite transient response time, but for a low-current application like a mic pre, the addition of a few additional capacitors on the load side of the regulator solves that problem.
Hello all,
Well, this is pretty cool. I appreciate your interest in the N72 kits, and I'd be more than happy to answer any questions you might have about them, or talk you through any construction issues or concerns you might have. I've gotten good feedback from the few intrepid kitbuilders out there who have already jumped in with both feet, so I think building the kit will be a good experience for most who try it.
As for power supplies, if you have a look at the "Parts List" page there are two Power 1 linear supplies that will work fine with the N72. Neither use toroidal transformers, nor are the transformers shielded, so if you go that route you might want to consider installing them in a separate enclosure, a la the George Massenburg gear, among others. I'm currently working on a power supply design that will fit nicely into the 2U Bud enclosure I've used for my prototypes, but that won't be available for at least another month. For those that are interested in building their own, I suggest you go to http://www.national.com and get a datasheet for the LM317 regulator. It'll tell you just about everything you need to know.
BTW, the reason to use a regulated supply is that an active regulator reduces the output ripple by an order of magnitude or more over a simple RC filter, is much less expensive than using big inductive chokes, and allows the use of smaller filter caps than you'd otherwise have to use. It's true that for some applications an LM317 type regulator might not be optimal, since they do have a finite transient response time, but for a low-current application like a mic pre, the addition of a few additional capacitors on the load side of the regulator solves that problem.
D
Dan Kennedy
New member
I really can't do a kit project, for all of the reasons above, plus the amount of support time needed.
But I do recommend Tim's board. I saw it in Sacramento at the TapeOp conference and it looks good. It's not all you need, but Tim seems willing to provide the support.
Is it a 1272? No, is it close yes. It does have differences, as do my products. It is a well done version, and if you make it all the way to the end of the project you will have a piece of gear to be proud of. It won't be cheap, it won't be easy, but what of any value is?
I don't know if a whole bunch of you ganging together to buy one of preamps is enough inducement either
But I do recommend Tim's board. I saw it in Sacramento at the TapeOp conference and it looks good. It's not all you need, but Tim seems willing to provide the support.
Is it a 1272? No, is it close yes. It does have differences, as do my products. It is a well done version, and if you make it all the way to the end of the project you will have a piece of gear to be proud of. It won't be cheap, it won't be easy, but what of any value is?
I don't know if a whole bunch of you ganging together to buy one of preamps is enough inducement either
H
h kuhn
New member
Dan or Tim,
how much of a difference does the board layout itself make in a neve-clone? I have read a couple of times that the layout itself can make a difference in sound. Can you confirm this observation? I am intrigued by the thought of buying Tim's board instead of going through the hassle of etching my own board (I will build a neve clone, that is for shure).
Have you an opinion about the sowter x-formers? Do they sound very different from the ones Tim recommends?
regards
Harald
how much of a difference does the board layout itself make in a neve-clone? I have read a couple of times that the layout itself can make a difference in sound. Can you confirm this observation? I am intrigued by the thought of buying Tim's board instead of going through the hassle of etching my own board (I will build a neve clone, that is for shure).
Have you an opinion about the sowter x-formers? Do they sound very different from the ones Tim recommends?
regards
Harald
crawdad
Dammit, Jim, Shut Up!
h kuhn said:
h khun--Yes, you are right. I'm just not at home with electronics, I suppose. The information is out there and Tim Ryan seems willing to support us DIY guys, so that helps. As for the phantom power thing, I only understood when you said I could get a phantom power unit. Doh!
See, I was assuming that this pre, like all the ones I have, would have phantom power built in, which could be switched in or out. Am I to assume that the Neve pre's didn't have phantom power either?
Ah, I can get confused easily. I'm good at music and embarrassed in electronics! Anyway, thanks for the comments!
D
Dan Kennedy
New member
The board layout can indeed affect the sound of the preamp.
Tim's looks good, but I haven't heard it. I certainly wouldn't hesitate to buy it.
Etching your own boards is a royal pain in the butt. I've done it on and off for years, and just don't bother anymore. I use a PCB house up in Canada called Alberta Printed Circuits for my early prototypes or just plain old down and dirty projects. For less than $30 or 40 a circuit board I can have stuff back in three days, no muss no fuss. Compared to all the mess and chemicals and fishtanks and crap its well worth it. They can do 12mil lines and spaces, which I've only managed over a moderate sized board a few times.
I like the Sowters, that's why I worked with them. They are not identical, in fact they fix the problems in the old Neve iron, so if your looking for a clone, they aren't the way to go.
Tim's looks good, but I haven't heard it. I certainly wouldn't hesitate to buy it.
Etching your own boards is a royal pain in the butt. I've done it on and off for years, and just don't bother anymore. I use a PCB house up in Canada called Alberta Printed Circuits for my early prototypes or just plain old down and dirty projects. For less than $30 or 40 a circuit board I can have stuff back in three days, no muss no fuss. Compared to all the mess and chemicals and fishtanks and crap its well worth it. They can do 12mil lines and spaces, which I've only managed over a moderate sized board a few times.
I like the Sowters, that's why I worked with them. They are not identical, in fact they fix the problems in the old Neve iron, so if your looking for a clone, they aren't the way to go.