presto 45 speed adapter
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
presto 45 speed adapter
i was wondering if anyone knew where i could get hold of one of these, some bloke i chatting to said they aint around no more to purchase but i could get one machined up so my k8 runs at 45 just wondering if anyone had one for sale or know where to get one
Simon I will get info from doug but I need to know what motor you are using???? Is it the bodine 60Hz one using a 110v mains transformer???
You could use a ac motor controler to change the frequency of the drive voltage got get 45 using the 33 motor pully.
PM me with what setup you have as I will have to recalculate the dimensions if you are using the 60hz 120v motor in england with 240v to 110v transformer as the motor is frequency controlled. All you do is add 20% to the diameter of the motor pully..
You could use a ac motor controler to change the frequency of the drive voltage got get 45 using the 33 motor pully.
PM me with what setup you have as I will have to recalculate the dimensions if you are using the 60hz 120v motor in england with 240v to 110v transformer as the motor is frequency controlled. All you do is add 20% to the diameter of the motor pully..
!Work or Bang Time!
45 RPM
Hi:
I see I was referred to here.
And I got the email from Amp Doc today.
The K8 uses an entirely different motor and drive pulley from the 6N or 8N
So the pulley I have from Amp Doc is nothing at all like it. I do have a K8 myself so am familiar with both.
Amp Docs idea of changing the motor frequency is probably the best way to go. This could give you almost infinite speed adjustment also.
Doug
I see I was referred to here.
And I got the email from Amp Doc today.The K8 uses an entirely different motor and drive pulley from the 6N or 8N
So the pulley I have from Amp Doc is nothing at all like it. I do have a K8 myself so am familiar with both.
Amp Docs idea of changing the motor frequency is probably the best way to go. This could give you almost infinite speed adjustment also.
Doug
I have two different '45' adapters for the 6N and neither work well. I had a machinist make a complete motor pulley by measuring the diameter of the 45 adapter, then turning a 45/78 pulley. Works sooo much better than the 'adapter'. Too much vibration because it doesn't fit the shaft tightly and translates into the recorded groove.
Nigel from the UK suggested to use Audacity from a computer sound card then output to the input of the K8
I will post what he sent me via e-mail.
I guess your lathe does 33 and 78. That’s what my Presto one does. If you
are importing from the USA it will operate at 60hz so your 33 and 78 will
be 27.7 and 65 rpm.
You will have to get a new speed spindle made for the UK 50hz, so instead of getting the 33rpm, get it made for 45rpm instead.
download Audacity (free audio software) off the web. It has a
speed conversion thing, so you can convert 33 to 45 and anything in between.
So you can route your soundcard output into the lathe, and convert from 33
to 45 and the cutter will cut it all at the correct speed then. Before I had
my spindles made, I did this and it worked fine. At least you can play with
it instead of it sitting around till you get a spindle. Alternatively, bang
a sleeve over the 33 spindle and file it down until it plays at 45. Its not
a bodge - ALL the American jukeboxes imported over here with similar motors were converted like this in the day. Its just re-gearing really.
**********************************************
Higher speed transfers and 78 rpm dubbing
Because Audacity can change the speed of recordings, it's possible to record your 33 1/3 rpm records into Audacity at 45 rpm (so transfer them more quickly), or you can record 78 rpm records at either 33 1/3 rpm or 45 rpm (even though the turntable does not offer 78 rpm). Once the track is recorded into Audacity, simply select all the track by clicking in the Track Panel (where the mute/solo buttons are) and click Effect > Change Speed. In the "From" box choose the speed you played the record at (e.g. "33 1/3" or "45") and in the "To" box choose the speed you want to convert the recording to (i.e. the speed it should be played at according to the label).
Where you are recording at a faster speed than normal e.g. recording a 33 1/3 rpm record at 45 rpm, it's recommended to set the sample rate in the Project Rate button bottom left of the Audacity window to a higher sample rate than 44.1kHz to ensure you record the full audio spectrum. For recording 33rpm records played at 45rpm, a sample rate of 60k or more is needed to record the full 20kHz spectrum. If 44.1k sample rate is used when recording, the final audio will be limited to 14.8kHz bandwidth.
Accelerated recording does not give the best sound quality, for two reasons:
First, the playback equalisation curve is being applied incorrectly in the record deck preamp. While correct for normal speed play, all music content is frequency shifted during accelerated play, and equalisation is therefore incorrect.
Secondly, cartridges behave poorly beyond 20kHz, and an accelerated deck is using the cartridge at up to 27kHz to play back audio content of up to 20kHz. Consequently distortion will rise, high frequency response will be more peaky, and generally the highest frequencies will be lost. How much of an issue this quality loss is depends on the cartridge, but it will always be present, with no cartridges giving as good performance to 27kHz as they do to 20kHz.
Special note on 78 rpm transfers
Where you are recording 78 rpm's, there is a problem in that the pre-amplification built into the turntable is designed for records made from the 1950s onwards. This is because the pre-amplification not only provides the necessary amplification for the cartridge signal that's sent to Audacity, but applies what is known as "RIAA playback equalisation" to it. This equalisation is essential when playing records made from the 1950s or later, as it cancels out the high frequency biassed "RIAA recording equalisation" that such records are cut with, and so makes them sound normal again. The problem is that as most 78 rpm records were not cut with such a strong high frequency bias, they therefore sound dull if played through modern equipment like your USB turntable that applies RIAA playback equalisation.
So to make a fully professional job of transferring your 78 rpm's you would be advised after recording to use Effect > Equalization in Audacity and draw and apply the reverse of the RIAA playback curve, that is, the green recording curve shown in the diagram here . This will cancel out the unwanted RIAA equalisation then you can apply one of the 78 rpm playback curve presets supplied with the Audacity Equaliser. Note that these curves are generic and in practice many different equalisations were used according to the record label or even the recording engineer. You can see turnover and rolloff information for many 78s and pre-RIAA labels here . (A PDF Reader such as Adobe is needed to read this document.)
I will post what he sent me via e-mail.
I guess your lathe does 33 and 78. That’s what my Presto one does. If you
are importing from the USA it will operate at 60hz so your 33 and 78 will
be 27.7 and 65 rpm.
You will have to get a new speed spindle made for the UK 50hz, so instead of getting the 33rpm, get it made for 45rpm instead.
download Audacity (free audio software) off the web. It has a
speed conversion thing, so you can convert 33 to 45 and anything in between.
So you can route your soundcard output into the lathe, and convert from 33
to 45 and the cutter will cut it all at the correct speed then. Before I had
my spindles made, I did this and it worked fine. At least you can play with
it instead of it sitting around till you get a spindle. Alternatively, bang
a sleeve over the 33 spindle and file it down until it plays at 45. Its not
a bodge - ALL the American jukeboxes imported over here with similar motors were converted like this in the day. Its just re-gearing really.
**********************************************
Higher speed transfers and 78 rpm dubbing
Because Audacity can change the speed of recordings, it's possible to record your 33 1/3 rpm records into Audacity at 45 rpm (so transfer them more quickly), or you can record 78 rpm records at either 33 1/3 rpm or 45 rpm (even though the turntable does not offer 78 rpm). Once the track is recorded into Audacity, simply select all the track by clicking in the Track Panel (where the mute/solo buttons are) and click Effect > Change Speed. In the "From" box choose the speed you played the record at (e.g. "33 1/3" or "45") and in the "To" box choose the speed you want to convert the recording to (i.e. the speed it should be played at according to the label).
Where you are recording at a faster speed than normal e.g. recording a 33 1/3 rpm record at 45 rpm, it's recommended to set the sample rate in the Project Rate button bottom left of the Audacity window to a higher sample rate than 44.1kHz to ensure you record the full audio spectrum. For recording 33rpm records played at 45rpm, a sample rate of 60k or more is needed to record the full 20kHz spectrum. If 44.1k sample rate is used when recording, the final audio will be limited to 14.8kHz bandwidth.
Accelerated recording does not give the best sound quality, for two reasons:
First, the playback equalisation curve is being applied incorrectly in the record deck preamp. While correct for normal speed play, all music content is frequency shifted during accelerated play, and equalisation is therefore incorrect.
Secondly, cartridges behave poorly beyond 20kHz, and an accelerated deck is using the cartridge at up to 27kHz to play back audio content of up to 20kHz. Consequently distortion will rise, high frequency response will be more peaky, and generally the highest frequencies will be lost. How much of an issue this quality loss is depends on the cartridge, but it will always be present, with no cartridges giving as good performance to 27kHz as they do to 20kHz.
Special note on 78 rpm transfers
Where you are recording 78 rpm's, there is a problem in that the pre-amplification built into the turntable is designed for records made from the 1950s onwards. This is because the pre-amplification not only provides the necessary amplification for the cartridge signal that's sent to Audacity, but applies what is known as "RIAA playback equalisation" to it. This equalisation is essential when playing records made from the 1950s or later, as it cancels out the high frequency biassed "RIAA recording equalisation" that such records are cut with, and so makes them sound normal again. The problem is that as most 78 rpm records were not cut with such a strong high frequency bias, they therefore sound dull if played through modern equipment like your USB turntable that applies RIAA playback equalisation.
So to make a fully professional job of transferring your 78 rpm's you would be advised after recording to use Effect > Equalization in Audacity and draw and apply the reverse of the RIAA playback curve, that is, the green recording curve shown in the diagram here . This will cancel out the unwanted RIAA equalisation then you can apply one of the 78 rpm playback curve presets supplied with the Audacity Equaliser. Note that these curves are generic and in practice many different equalisations were used according to the record label or even the recording engineer. You can see turnover and rolloff information for many 78s and pre-RIAA labels here . (A PDF Reader such as Adobe is needed to read this document.)
Re: presto 45 speed adapter
sorry to bring this thread back to life.
has anyone made a adaptor for the Presto K8 to cut at 45?
i know there is the adaptor to cut 78s
has anyone made a adaptor for the Presto K8 to cut at 45?
i know there is the adaptor to cut 78s
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ROLANDJAYS
- Posts: 287
- Joined: Sun Apr 14, 2013 3:48 am
Re: presto 45 speed adapter
I can make you one . do you have any dimensions?
ill make a bunch and split the order between all the users .
ill make a bunch and split the order between all the users .
Re: presto 45 speed adapter
I've only ever seen one or two that were included with a K10 machine on eBay. I have the flyer/instructions for the adapter system, but I've never seen one for sale standalone.
Re: presto 45 speed adapter
i wouldnt know the outside diameter of the spindle. i have one for my presto 6n i wonder if its the same as that?
i guess i will have to experiment when i get home.
i guess i will have to experiment when i get home.
Re: presto 45 speed adapter
No, it's a different size because it's proportional to the size of the platter. I'll try to find the calculator to do the math to determine what size it should be.Jccc wrote:i wouldnt know the outside diameter of the spindle. i have one for my presto 6n i wonder if its the same as that?
i guess i will have to experiment when i get home.
Re: presto 45 speed adapter
good looking out.
knowing me i wouldve made some ghetto rigged adaptor to make it fit only to find out it cuts the wrong speed!
it would be awesome to have a adaptor to cut 45s with the k8.
its a really awesome machine once you figure out the sweet spot for loud cuts
knowing me i wouldve made some ghetto rigged adaptor to make it fit only to find out it cuts the wrong speed!
it would be awesome to have a adaptor to cut 45s with the k8.
its a really awesome machine once you figure out the sweet spot for loud cuts
Re: presto 45 speed adapter
Len Horowitz can get you one. What I do for 45 rpm on my k8 is I record the song on a tascam portastudio 414 with the variable tape speed all the way up then when I cut the record I move the tape speed down so that a G note would sound like the next lowest D or C I forget which. The point is that 16, 33, 45 and 78 are not just random speeds they are designed to all share fifths. Now I really can't recall which fifth it is but if you were to play back a record with a single note on it and go from speed to speed, starting at the slowest it would either sound like tuning a cello or like tuning a bass I forget which. Hope this helps. Also when you cut it that way you can boost the eq better and louder for super spicy mono cuts. My favorite to use is GreatValue brand black picnic plates from cash-n-carry. Its less than 20 bucks for 500 of them. And make friends with someone who has a still press. And try not to drill more than ten at a time. And use crappy metal needles at first until you know what you're doing. And if your onboard amp starts smoking and shooting flames and you don't know how to fix it be real careful about ohms and volts and all that and doublecheck everything when rigging up an outside amplifier (use the in-line fuse to the cutting head too). If you have the old horseshoe they're 8 ohm and if you have the fancy pants rich kid c series shiny one that's 500 ohms. But if you're smart you'll double check that. Ok I'm done for now good luck
<\\\\\\\\\\\\\\\\\\\\\[[[[[[[\/]]]]]]]\\\\\\\\\\\\\\\\\>
Recordette Sr.......Presto K-8
Recordette Sr.......Presto K-8
Re: presto 45 speed adapter
It is based on diameter, I usually use radius x 2 because it's easier to measure center to edge. Measure your platter for it's diameter. Then use this calculator:
http://www.culvermotor.com/Engineering-Formulas/Pulley-and-RPM-Calculator.html
RPM1 - Diameter1
RPM2 - Diameter2
RPM1 = speed of motor (1800rpm)
Diameter = X (size of new 45 rpm adapter)
RPM2 = 45
Diameter2 = Platter Diameter
Using the calculator above, Diameter1 will be selected as the X to solve for with your other variables entered. Hit the button and you have your answer. This number should be between the size of the spindle adapter and the 78rpm adapter. If it's not, then I've mismatched the variables.
http://www.culvermotor.com/Engineering-Formulas/Pulley-and-RPM-Calculator.html
RPM1 - Diameter1
RPM2 - Diameter2
RPM1 = speed of motor (1800rpm)
Diameter = X (size of new 45 rpm adapter)
RPM2 = 45
Diameter2 = Platter Diameter
Using the calculator above, Diameter1 will be selected as the X to solve for with your other variables entered. Hit the button and you have your answer. This number should be between the size of the spindle adapter and the 78rpm adapter. If it's not, then I've mismatched the variables.
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Steve E.
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Re: presto 45 speed adapter
It's a horrible thing, those adapters....at least the ones for a 6N. It seems they tend either to be too tight, and then they get stuck, or they are too loose, and they rattle. piaptk can tell horror stories of one he bought from me, a spare I had.
I have never done this, but I like Alan Graves' solution of machining a piece to turn the 78 speed into 45, and making a new rubber roller to match. Again, this is for a 6N, and I don't know if this sort of solution would work for a K8.
http://www.lathetrolls.com/viewtopic.php?t=3149#p20647
I have never done this, but I like Alan Graves' solution of machining a piece to turn the 78 speed into 45, and making a new rubber roller to match. Again, this is for a 6N, and I don't know if this sort of solution would work for a K8.
http://www.lathetrolls.com/viewtopic.php?t=3149#p20647