Project "Groove Scribe"- A DYI stereo 45/45 head.

[sakuszi]

real and true recording only did Mr Opcode 66 head Bladerunner, and real recordings

[EpicenterBryan]

sakuszi, I get it.
I'll incorporate that kind of stuff in the next video. I'm sad people (like you) would even think that what I am doing is not real, but I get it.

For tonight, I have some things to share for everyone else.
First off, I needed to determine a reference level that would match a 5cm/s test record like the CBS STR100. So I cut some test bands.

Here is a cut that is pretty close. It was a cut with no EQ and No Feedback.
As I have posted before I used Wayne's flat preamp to play the disc back. And I used a pair of Teac meters to verify those levels compared to the test record. The measurements were reasonable. +1.25db left, and -0.25db right. I already have posted that the amp channel balance is off by 0.6db. So overall, I'm OK with that.

0.8v drive.jpg

I had a big scare last night. A few days ago I noticed that the right driver feedback coil was rubbing on the magnet. Thankfully I installed Teflon tape over the coils before I assembled things. But I could see a frequency response change on that driver if I moved it slightly out of alignment. Since the driver connection to the stylus holder was glued, I tried loosening the driver mount slightly and moving the body a little bit and tightening things back down. That worked (as I thought at the time) but last night the right channel started blowing fuses on my Phase Linear 400 power amp. I have blown fuses many times before, as anyone who is messing with feedback has. But this time was different. I could blow a fuse with no output signal. And I since I ran out of 0.5 amp fuses, I even had a 1.5A fuse blow!

It turned out that the right driver had developed a "partial" short to ground. The coil tested fine on it's own, but was no longer isolated from ground. The other driver was totally isolated from ground. That implied that the voice coil had rubbed on the magnet structure. I ended up loosing up the driver, letting it rest where it wanted to rest, and bending the push rod with needle noose pliers until the feedback coil was centered.

IMG_4521.JPG

I'm not thrilled about that fix, but it worked. It's the nature of making things one at a time by hand.
So that's the update for tonight.

Bryan

[Snug Music]

I had a big scare last night. A few days ago I noticed that the right driver feedback coil was rubbing on the magnet.
I could blow a fuse with no output signal. And I since I ran out of 0.5 amp fuses, I even had a 1.5A fuse blow!
It turned out that the right driver had developed a "partial" short to ground. The coil tested fine on it's own, but was no longer isolated from ground.
I'm not thrilled about that fix, but it worked. It's the nature of making things one at a time by hand.

Oha...
Bryan..we feel right to you. That's pretty heavy when that happens. Wishes you a lot of happiness and runs smoothly next time, everything!
We all believe so strongly in you!
We also had days where we nearly died of despair. This raises a very out of the curve.
If we were near, would comes and drink with you a beer, than it would run again determined.
Wishes you from here Bremen-Germany very much success.
And remember, we are all in thought with you!


best Regards...
Scotty & iLLe
SNUG MUSIC

[aaron]

I agree. Your work is very awesome and inspiring.

[EpicenterBryan]

If we were near, would comes and drink with you a beer....

That would be very fun! I would like to hang out with all of the lathetroll people. You guys are awesome!

I agree. Your work is very awesome and inspiring.

Thanks aaron. You didn't by chance live in Oregon or Washington in the past did you? I have only known 2 people with the same spelling.

As for the update tonight -

I've fought with some goofy looking swarf, and a mechanical whistle while cutting test discs. And then I remembered a few things from last year that I ran into on my previous head versions. The issue didn't come up when I was doing testing with John's head, and I tried the same stylus I used for those tests. I should have remembered the lesson learned. John's head is very well machined - totally professional. I could install a stylus and it would self align because of the tight tolerances and machined surfaces especially the hole for the stylus, but also the set screw that forces the stylus to be facing straight forward.

My head has a very sloppy tolerance where the stylus is inserted. But I discovered tonight that a nylon set screw I salvaged from my bag of spare parts from a previous version of a head is not straight on the end, so the stylus could rotate out of center when tightened. What makes it worse is that if I remove the stylus, the head has to be realigned since there is no guarantee it could be exactly perpendicular - since the hole diameter is too large on the salvaged stylus holder. Little details like this are easy to forget for amateurs like me, especially when some time has passed. OR, am I just getting too old?

Saturday morning, I will machine a new aluminum set screw that is flat on the end. And I will make sure the stylus is absolutely perpendicular (I may need to adjust the head) and I will make sure the new set screw forces the stylus to stay tangent to the groove diameter. Then I'll do a cut and post it.

As far as the feedback and all that, there may be improvements to be made but it's time to do audio for people to hear. I would have preferred to wait until I nailed everything down as well as possible but I think I'm as close as I want to screw around with this....

Bryan

[EpicenterBryan]

Good news and bad news.

First, the good news: below is the first audio test disc of Groove Scribe with feedback.
The bad news is that I blew a driver while doing a demo of how the feedback works. It's all explained in the video below. It even shows the exact second I blew the driver and what I did wrong! The video at the end shows the "disc messing" that you will hear in the full playback audio posted below.

Now for the Music:
Groove scribe disc playback (including messing with the disc as seen in the video):
https://soundcloud.com/epicenterbryan/groove-scribe-test-playback-with-disc-messing/s-5rDhx
Source audio: Declipped.
https://soundcloud.com/epicenterbryan/dive-deep-declipped/s-YjERX
Credits:
"Dive Deep (Loveshadow remix)" by spinningmerkaba
2015 - Licensed under Creative Commons Attribution Noncommercial (3.0)
http://ccmixter.org/files/jlbrock44/50488

And here is the video:

Enjoy, and please raise a toast to our departed left driver friend. It will be sadly missed. I'm pretty sure I had 0.5A fuses installed but my eyesight is not what it once was!

Bryan

[sakuszi]

very well recorded, but why so short recording? look forward to a long recording, Brayan understand, a lot of work, nice music equipment

[EpicenterBryan]

very well recorded, but why so short recording?

You must not have listened to the audio file that was recorded while the video was being made. Here is the file again, and the song is being played full length:
https://soundcloud.com/epicenterbryan/groove-scribe-test-playback-with-disc-messing/s-5rDhx

You can play this audio and the video at the same time and you will see this is the actual record playback that was recorded by my protools system as the video was shot - the is played full length, even after I turned off the video camera.

Bryan

[Snug Music]

hey Bryan,

...thanks again for the flowers.
Yes, that would certainly become a funny troll Party to make with you.
Unfortunately, we're so far away.
But someday for sure!
Very great video of you, thanks for posting! Good Cut! But you're also a great troll friend.

Regards Scotty

[Radardoug]

Sakuzsi who are you? You seem to be a troll of the worst kind. Perhaps you can enlighten the forum on exactly who you are, and why you feel you can comment on disc cutting. All I have seen from you is uninformed abuse.

[inspector77]

Amazing Bryan!, congratulations!!!!

[Snug Music]

Sakuzsi who are you? You seem to be a troll of the worst kind. Perhaps you can enlighten the forum on exactly who you are, and why you feel you can comment on disc cutting. All I have seen from you is uninformed abuse.

Thank Radardog,
I think you're talking here just a few people from the soul.
Many times, I also believe that Sakuszi not realize what he writes here!

thx..Radardog

regards Scotty

[sakuszi]

Hello ! , what's going on here ? Did I say that evil is recorded? It is recorded as well, but for professional recordings still far!
I am critical of my recordings, I think that is far from professionalism, I checked the speakers Brayan, are not a good way to go head Brayan he said it.

[Radardoug]

That doesn't tell us anything! And your English is very bad and contradictory! And its Bryan!

[Snug Music]

Hello ! , what's going on here ? Did I say that evil is recorded? It is recorded as well, but for professional recordings still far!
I am critical of my recordings, I think that is far from professionalism, I checked the speakers Brayan, are not a good way to go head Brayan he said it.

Saku,..
This is not meant. It is the way you express it do! We all here at Lathetrolls appreciate each other very much. Who has problems is helped here. Who ask, who is allowed to post here and also gets 100% response! Everyone here appreciates the work of others. Who but continuously the work of other calls into question ( "this is not real!" Etc.), arises quickly sidelined and draws the ire of other up. So, just once have a bit more confidence and not also say "it would not be professional works / recordings make the people here (with respect to the postings about opcode66!) ...... U now it ??!) Otherwise, seem to you yes be a nice person. But such statements can annoy other people very nice and drive up the wall!


Scotty

[sakuszi]

I said that the speakers that applied Brayan are wrong, I bought a set of these speakers, quit immediately, the actual frequency response of the head is not greater than 6 kHz. The amplifier was working with full power, burnt coil but the band was not higher than 6kHz. I resigned from the speakers. I bought the speakers Boschman MM6 they record these speakers to 12kHz

[sakuszi]

Other elements to the head, such as cones, which has developed Bryan are very good. I did also EQ Caruso, based on a scheme Flozki, but a better solution was found in only 31 band graphic equalizer two channel

[EpicenterBryan]

Hey guys, Great news!

The driver is not blown - but it broke a wire off the coil inside (the black one). It should be an easy fix. I think I will also redo the red connection as well. These coils have been been in and out of drive bodies many times, so it's reasonable to think all that extra movement from my little mistake caused the final break.

IMG_4529[1].JPG

While the heads off I'm going to look into why the channel separation is not very good although the feedback output is. I think it's push rod related and the drivers are going out of alignment rather than producing correct vertical (L-R) movement at the connection to the stylus holder. I have an idea for a fix if that's what is going on.

I checked the speakers Brayan, are not a good way to go head Brayan he said it.

sakuszi is correct. I did say that I don't recommend these drivers for a DIY project at this point. I've learned there are just too many thing that have to be done to reduce the moving mass among other things. And to add feedback - that really complicates things. For non-feedback, you guys are having very good success with tweeters. I'm not sure if there is an easy solution for adding feedback to them but I'm sure someone will figure that out. My attempt at using a phono cartridge failed - mainly do to not having proper shielding in place from day one. But I don't know for sure. In theory it should have worked but I gave up and went this way (with feedback coils on the rods).


Bryan

[sakuszi]

This is not good news, but easy to solder the cable, already did that, good links are telephone copper, very flexible.
Brayan, try to do the same, but the company Boschmann car speakers, tweeters, bandwidth is much higher

[Sillitoe]

These drivers seem to have had the greatest impact in the development of a successful "DIY" feedback head that we've seen so far.
Look at Cuiens and his ZEZ, good results using a modified version of this driver and then quite amazing results with it's smaller sibling.

I'm sure his work was informed by this thread to some extent.
The work here shouldn't be dismissed, it is valuable and significant.