Presto 6N??

[JayDC]

Hello,
Thanks for setting this site up, I have been interested in this subject for a long time. Nice to finally find a place to talk to people "in the know"..

I'm a indie producer of dance music, and I have been producing music since I was 14 (13 years). I have a couple of vinyl release to date, and a good collection of records, and dubplates. I have always wanted to record to vinyl since I started to make music.

Seems these days cutters are harder, and harder to find. I remember the days of Jah Freedom, Scrunch, aardvark and the like, and used them a good amount.

Now to the point.

I'm very interested in get myself a lathe for personal use. I really would like a hands on experience in making a great sounding record. Most of my presses definately could have sounded better. I use to think it was the cutters fault, but now Im starting to realize it was probly mine.

There is alot more to getting a record to sound good, then a CD or dat.

That being said.

I have found a cool little Presto 6N with a Presto 90-B amp, a 1C cutter head, vacuum attachment, and a microscope.

Would this be an okay unit to start with?.. I would like to cut in stereo, and something tells me this is a mono machine. That's okay for right now, as long as I can upgrade it, is that possible?..

I have not found any information on the cutting head, and I'm wondering if a stylus is available for it?..

Are apollo's lite disc's okay?.. I have only ever had apollo dubs in my collection, they are not the best for DJ's unless your just playing the track. Seems to scratch burn easliy even when cueing. Plus they are WAYYYYY Heavy..

I'm not really one for PVC..

I have also looking at the vinylium dubplate machine which is a little out of reach ATM, but I could liquidate my laser collection to raise up the funds if it's truely worth it.. ( i really like the fact about being able to upgrade the machine to cut masters, which is something I like to get to once I master the art form of using the machine.) although I don't like the idea of using a Technic 1200 for the platter..

Please guys.. A Little help..

Oh.. I have good techincal experience, I'm a sound engineer, and into electronics as a hobby.

thanks for the site!!!!!!! can't wait to meet some of you gurus on here!

[cuttercollector]

Hi. Please excuse this reaction, but quite frankly your post made me somewhat mad and jealous.
I guess there are a lot of people on this list somewhat like you.
I am a technician, not a musician. I am 52 years old. I am now trying to sell off most of what I have to make ends meet. I am probably unemployable at this point except for a "McJob". I have been fooling around with recording and audio since well before I was 14.
Mostly what that got me as a career was a lot of crawling and pulling wires and connecting things and really actually making systems work while others got the glory and most of the money.
There, I feel a little better. Thanks for indulging that.


Yes, all Presto cutters are mono. Well, they technically made 1 prototype stereo one which was a copy of the Westrex under license from them. They do not have feedback. Most of the time they were the workhorse recorders at radio stations in the 40s. they were mostly meant to cut non microgroove 78 records. They have a top end of perhaps 8-10Khz and were not designed to cut at the levels expected today. Not to say that they were not used to cut some pop 78s at Capitol Records back in the late 40s. But for modern stereo at the levels desired for DJ stuff, which it sounds like you are into that scene, you need big $$$ and a pro stereo cutting system like Westrex Ortophon or Neumann. You probably can adapt one of the small stereo cutting heads like vinyl recorder or kingston to the presto lathe. You will need the associated stereo electronics chain, and to make sure your lathe can be operated at microgroove pitch. This may involve a finer pitch leadscrew and/or the drive mechanism. Some Presto lathes had a belt and pulley tree arraingement like a drill press to vary the lines per inch. Back to the mono Presto system. It is harder to find styli for these and what is available is not typically ones with heater coil wires. Most were later adapted to heated styli, but that requires a stylus heater power supply and perhaps winding your own coil. Most of all of this is very do it yourself. Everything from setting up eq curves for recording to making mechanical modifications to mount and allign heads on various machines. Spend a lot of time browsing through the past posts here and you will find a wealth of info. (some good some bad)
The bottom line is this is an art where you need good electronic and mechanical and musical skills to make a beautiful sounding record, but the rewards are great. I have never gotten there. I hope you do.

[JayDC]

Hi. Please excuse this reaction, but quite frankly your post made me somewhat mad and jealous.
I guess there are a lot of people on this list somewhat like you.
I am a technician, not a musician. I am 52 years old. I am now trying to sell off most of what I have to make ends meet. I am probably unemployable at this point except for a "McJob". I have been fooling around with recording and audio since well before I was 14.
Mostly what that got me as a career was a lot of crawling and pulling wires and connecting things and really actually making systems work while others got the glory and most of the money.
There, I feel a little better. Thanks for indulging that.

It's okay, I'm 27 and almost in the same situation. I was an engineer for touring sound systems, and I also worked at a local MEGACLUB. Both have closed the doors, but I still love my music. I also did some stuff with laser show system, and own a couple that the club let me have when they closed.

I don't really have too much school in me, other then audio stuff, and it's a hard to find a job when your competing against your old co-workers..

Any who..

I am not really trying to get into this to sell dubs. There are easier ways to make money, records are not one of them (at this point in time). I'd just be happy to beable to cut my original tracks to dubs, to learn more about the equipment, make it sound good. There are not that many people doing this sort of thing, and they are not getting any younger. If my generation doesn't have a handfull of people with this knowledge, it could be lost forever. Then my technics will be useless.

I'm currently looking for my first setup, and if anyone has such a system they don't use often, or are willing to part with. Let me know.

Transco seems to have presto styli, and if they fit this 1c head, then I might just go presto. If not, I'll have to keep looking, and saving..

[kd88]

I also am cutting with the 6N and the 1D cutter. The transco styli fit this cutter. Also, I was lucky enough to acquire a Fairchild head and a stylus heater. Dis-assembly of the heater reveals a simple transformer (AC, with rheostat and meter). This would not be hard to duplicate. You're heating up a nichrome wire, so a schematic for a foam cutter would be applicable. You cannot argue with the sure voice of experience: do not overheat the stylus. I found the most difficult thing to do was keep the nichrome whiskers from not touching the chip as it is sucked by the vacuum from the cut. When this happens, the hot lacquer falls onto the plate, ruining the cut, your plate, fouling the nichrome, the stylus, and making you a very unhappy camper. Such hurdles are all in the path for mastering this nearly lost art. IMHO.
Best of luck.

[JayDC]

Excellent!. I may have to plug you for infromation when I get this thing. I was thinking about the heater issue. Maybe a G scale train transformer, or a variac, will control the current good for the nichrome wire. I'll have to look into it. From what I understand is that you only need a few (2-5) volts of current to supply the heat. Does anyone know what temp you would need to get the stylus to melt the aceate but not burn it?..

[JayDC]

I went presto and bought a 6n with the 1C head and the 90-B amp. Can't wait to get it.. I'll post pictures when it arrives.

[flozki]

hello

i also have a presto, which i use for live on stage cutting and if transport is a problem. ok its still big but maybe one of the most compact stereo mastering lathes.

you can check a picture on
http://www.floka.com/lofi/portable_lathe.html

i will check for more pictures of the modification.. but at the moment there is just one i have.

[JayDC]

Master Flo..
They said it could not be done, but yet you did it!..

All I can say is HECK YEAH!!!!!!! Awesome.. you should sell a retrofit kit!!!!

[Jazzworkerbee]

Does anyone know where I can buy a cutting stylus? I've looked high and low with no love.

[JayDC]

Transco sell 'em..

[kd88]

Yeah, seeing this Presto mod really gets me to thinking...
Congratulations on a beautiful, well done, and truly inspirational modification. Flo, I think we need to re-invent the old Edison Prize to show our esteem.

My colleagues at the University of Illinois, who laugh at me when I talk about making wax records, understand the term 'bricolage'!

[JayDC]

I recieved the Presto cutter today!.. I setup the lathe, and made my first silent test cut. Seems okay. Maybe later I'll try some sound, once I get the amp setup. This one got a lot of nice features, like stylus heat, and a chip vaccum. Pretty nice.

[JayDC]

Wow!.. Finally got the system up and running, had a little snag since the on/off switch on the amp must have went bad durning shipping.

I fixed it with a similar switch from radio shack, and its working good. Sound is low and distorted. I'm going to replace the stylus tonight with a new one, and see if that helps at all. I hope its not a bad tube or something else.

If any of you Presto guys can give me some tips on setting up the system to record a good clean sound, please post!.. any help would be greatly appreciated.

Since this system is so old should I apply the RIAA curve to my source before sending it to the amp, or does the NAB RECORD Funtion on the amp set this? Maybe this is why my sound is so distorted..

Tonight I hope to hook up the heated stylus, and the vac, and try some real cutting. I only have 2 blanks, and I used most of one of them to make test cuts.

Hopefully you gurus will come out and help before I use the rest of my blanks..

Oh.. and to anyone using the Presto 90B amp, where should my VU needle peak? I want to boost the sound, but I'm affraid to blow the cutterhead...

Also.. I have a couple of styli, mostly from tranco, but one of them is in a tiny little presto tube, and the stylus tip is clear, is this a diamond?..

[JayDC]

Okay time to start answering my own questions.

The seller told me this about the VU meter needle question I had (this is for the 90B amp and 1C cutter)

take your test meter and put it on AC, play a song, dont let the VU meter goes over the red, measure the output of the Amp to get 3 volt that is the limit for the head, over that you will burn it. Try cutting with the switch on normal or RIAA, cut with low Bass and good High, because the Head reproduce heavy Bass. Also when you have time put a 3/4 fast blow fuse in line with the head to protect the head.

Very nice, I'm gonna get that fuse asap..

Now with a new heated stylus, and this method, I got a louder recording. Very pleasing, but the distortion is still a problem.

I think it may be a tube, since it's distorting from my monitor speaker as well. When I lower the source volume, I get a loud buzzing / howling sound that takes over, when I up the source I'm getting a distorted sound, mostly on the bass, but the highs sound a little crunchy too..

The buzz reminds me of the faint buzzing when you record audio from a T.V. (you know what I mean).. Sort of a 60hz ground loop buzz, maybe.. Although it's effecting the highs too.. Which a ground loop doesn't usally do..

I dunno I'm thinking a osciloscope may help me with this..

I'm also going to try grounding the amp, and see if that makes a difference.

[cuttercollector]

Have you restored the amp?
That is, checked and replaced all bad tubes and capacitors? Checked to see if power supply voltages are up where thy should be? Have you put it on a bench with a distortion analyzer and verified it's undistorted power output is up to spec? You should use a scope and look at the output waveform.
The fact that there is hum probably suggests bad power supply components.
Finally are you driving it with a proper level undistorted signal and on the other end, is your cutter functioning prpoerly (no shorted windings and magnetized properly etc.) and is it conected to the correct output impedance tap on the transformer for the cutter?
All of the above can cause poor low level before distortion.

The amp probably has some record eq but probably not RIAA.
I would supply the difference between it's curve and RIAA with another eq to make the whole thing flat as you could to RIAA playback within the range of what it is capable of. Don't expect flat 20-20K at high levels with old equipment.

[JayDC]

Have you restored the amp?
That is, checked and replaced all bad tubes and capacitors?

No, but that is the next on the list, I have a tube tester inbound. It looks like it will be about $120 in tubes if I replace them all. I have not check for the availablity of capacitors yet. I am in the process of replacing the wiring in the turntable, head, and amp. They are all chewed up.

Check to see if power supply voltages are up where thy should be?

No, but I have the manual, so I should beable to find that information.

Have you put it on a bench with a distortion analyzer and verified it's undistorted power output is up to spec?

No, what is this?..

You should use a scope and look at the output waveform.
The fact that there is hum probably suggests bad power supply components.

Yeah, that what I was thinking.

Finally are you driving it with a proper level undistorted signal and on the other end, is your cutter functioning prpoerly (no shorted windings and magnetized properly etc.) and is it conected to the correct output impedance tap on the transformer for the cutter?

The singal is not distorted before sending it to the amp, I made sure of this. The cutter seems to be working properly, and I'm going to remove it from the lathe, and give it a close inspection. It is connected to the correct outlet for the cutterhead off the amp. The sound from the record matches the sound from the amp's speaker. too bad it sounds like crap either way.

All of the above can cause poor low level before distortion.

The amp probably has some record eq but probably not RIAA.
I would supply the difference between it's curve and RIAA with another eq to make the whole thing flat as you could to RIAA playback within the range of what it is capable of. Don't expect flat 20-20K at high levels with old equipment.

I'm not expecting 20/20K @ +6 or 8db, I'd be happy with something around 40/10K @ +2db. Actually, 60/10K @ -.05db 24bit196Khz digital is how I master my 2 track anyway (well I guess 1 track.. hehe). Humans can't really hear much over 10K, and everything under 60 adds mud, anyhoo...

Thanks for your reply, and I hope to plug you for more information as this journey progresses.

If I can get my hands on a vinylium head, and electrics, I think I may be in bussiness (for myself). 16" platter = 14" basement cut masters, talk about underground.. hehehe...

[cuttercollector]

Yeah. I would guess if you really want this system as good as possible you probably will have to replace a few coupling and bypass capacitors in the amp, probably the main filter capacitors in the DC amp supply and a few tubes here and there including outputs. make sure you use a good mutual conductance tube tester to really get an idea if a tube is just weak or ok. A simple emmission tester will typically tell you only of gross failure.
Once you verify that the amp has good power supply voltage with no hum, and the circuits are all working correctly, tubes are good etc., if you can find someone with an audio distortion analyizer and a scope on their test bench it would be good to see if your amp is meeting original spec for distortion level and power output. The amp is run into a load with test tones and brought to clipping, then backed off slightly to where the output waveform is a normal sine wave and a meter measures the distortion level. You can do this at various frequencies. If the amp is supposed to do say, 40 watts at 1Khz with less than 1% distortion, and it does then you know that it is doing all it was designed to do. The other thing is I would highly suggest having the cutter professionally rebuilt, or at least checked by someone who does because any loss due to los of magnetization, which apparently is pretty common on old magnets, the condition of the damping material, making sure there is not a shorted turn in the winding etc, all lead to poor effeciency and loss of level before distortion. These systems were not capable of the kind of performance more modern feedback cutters were even at their optimum, so you really need all components to do their best to get anything really good and usable out of it.

[JayDC]

I really would like to have this equipment restored. Even if I do replace the head with a grampian, or vinylium in the future. The 90B amp looks so darn cool. Like something out of a nuclear reactor. I think it's the same one they used in "walk the line" when Jonny Cash made his first record.

I have read somewhere on here that there is a guy in West Virginia that services this gear. Thats within driving distance for me, so if anyone remembers who this guy is, and how to get in touch, I would be interested.

I'm pretty sure I have the knowledge to repair this equipment myself, but I lack some of the test equipment that this guy is sure to have. I'd like to talk with him and see what it would cost to have it looked at, and get it all repaired.

[JayDC]

I spoke to Gib over at West Tech, and he would gladly service this equimpent. The quoted price is less then I thought it would be, but I'm sure it will change once he takes a look at the head, and amp. The head should be fine, but I'm worried about the amp..

I guess we'll see whats going on..

[JayDC]

Okay here's some information on stereo head upgrades for the presto 6N.

Souri will not sell just the head, and feels that his head is too big for this lathe. (on a side note: Souri sell 14" PVC Disc's. He says some pressing plants will accept these as masters for 12" vinyl reproduction.)

The vinylium head will fit the presto 6N. I have talked to vinylium, and they quoted me 6850CHF for the upgrade. This included the Head, Electronics, built in stylus heat, a dummy head for calibration of the lathe, and a styli removal tool. They are looking into manufacturing a adpater plate to fit the lathe for easy installation. This comes to about $5,554.08 USD.. I'm thinking I'm going to go this way (since it's the only option.) Now I got to save me pennies..