I don't know---I'm always a little leery of things that are TOO automated---just somethin' else to break at the worst time! Alignment ain't all that hard, and unless you're exchanging tapes a lot, it only needs be done once in a while.....
I'm wondering....are you planning to SOCKET your ICs? Damn sockets cost about half the IC price!
That is an excellent point. One of my observations owning 4 of Otari decks and having worked on a few others is that most problems are due to bad caps, switches or corrosion of PCB due to degraded foam padding. There are occasional mechanical and bearing problems, but I've never seen a deck fundamentally that wasn't fairly easy to fix. In short I find them to be exceptionally reliable so I'm not too concerned about the complexity - getting parts is a huge problem so finding ones that are complete and approaching working order might be a challenge. So far I have only found one, sales over the past year seem to run in the $2200 - $5000 range so it's beyond affordable in my view and well into A-810 territory as well.
I love the idea though of being able to calibrate to each individual tape batch at the push of a button, and the fact that Dolby HX is included to maximize HF headroom. (I had an Otari with HX at one point)
My plan is to solder the adapters directly to the PCB as I am concerned about the additional stray capacitance from the socket (millmax), and adapter.
The LME49860 has a GBWP at unity gain of 55MHz so I'm also concerned about the small additional inductance between the supply pins and the supply...
I'm actually of the opinion that swapping the op-amps is a terrible idea unless of course I ultimately prove it works, and there is more than just a measurable benefit..
Not news to anyone who has spent a lot of time around tape decks, but if you splice your own leaders invest in a deluxe leader tape with easily discernible inside and outside faces.
I listen in low light conditions and since I started adding leaders and tails to the tape I have threaded the machine incorrectly on several occasions. If I notice no big deal, but I don't always notice..
Twice now I have threaded incorrectly and ended up with a reel of tape at the end of play with the coated side wound facing inwards. Rewind in this condition and the supply reel may wind inside out even when the tape did not run out first.
No panic this time and quickly fixed, the first time I lost several minutes worth of tape before I figured out how to solve the issue.
Just better not to wind it onto the reel wrong side out in the first place.
Never had this problem as a teen, I must be getting stupider as I get older.. LOL (Never had 10.5 inch reels of tape either with long leaders on it.)
I listen in low light conditions and since I started adding leaders and tails to the tape I have threaded the machine incorrectly on several occasions. If I notice no big deal, but I don't always notice..
Twice now I have threaded incorrectly and ended up with a reel of tape at the end of play with the coated side wound facing inwards. Rewind in this condition and the supply reel may wind inside out even when the tape did not run out first.
No panic this time and quickly fixed, the first time I lost several minutes worth of tape before I figured out how to solve the issue.
Just better not to wind it onto the reel wrong side out in the first place.
Never had this problem as a teen, I must be getting stupider as I get older.. LOL (Never had 10.5 inch reels of tape either with long leaders on it.)
Hi Kevin,
Well, that's it exactly (on sockets).
Leaders and tails used to have a very distinctive dull inner surface (towards heads) and a shiny surface (away from heads). I have seen recent tape where this isn't nearly as clear. Generally speaking you would play off and store tails out. There are very good reasons for doing this. Not the least of which is for controlled tension and an even pack.
-Chris
Well, that's it exactly (on sockets).
Leaders and tails used to have a very distinctive dull inner surface (towards heads) and a shiny surface (away from heads). I have seen recent tape where this isn't nearly as clear. Generally speaking you would play off and store tails out. There are very good reasons for doing this. Not the least of which is for controlled tension and an even pack.
-Chris
Fortunately, my friend found these sockets for me, which will do nicely, at only 18¢ each!:
8 pin DIP IC Socket Machined .3": Phoenix Enterprises -PE- Connectors IC Sockets Tools Cable Wire
Hi dotneck335,
Ahh, no. Those are from China and I have already tried them. The machining isn't very good for one.
You need to use Augat sockets if you intend to socket your chips. The best ones to reduce capacitance are the ones held on a carrier strip that are actually separate and they don't have any height to speak of. Kevin knows the ones I'm talking about. Once you solder them in, you remove the carrier and you just have a row of machined holes in the PCB with a row of thick pins on the solder side.
You can use the Augat sockets that look like the ones you linked to, but they will cost more than what was listed for the copies. Given what you are trying to do, wouldn't it be a complete waste to use crappy sockets? Those will be more difficult to insert the pins in, leading to bent pins at best. Speaking from experience here.
-Chris
Ahh, no. Those are from China and I have already tried them. The machining isn't very good for one.
You need to use Augat sockets if you intend to socket your chips. The best ones to reduce capacitance are the ones held on a carrier strip that are actually separate and they don't have any height to speak of. Kevin knows the ones I'm talking about. Once you solder them in, you remove the carrier and you just have a row of machined holes in the PCB with a row of thick pins on the solder side.
You can use the Augat sockets that look like the ones you linked to, but they will cost more than what was listed for the copies. Given what you are trying to do, wouldn't it be a complete waste to use crappy sockets? Those will be more difficult to insert the pins in, leading to bent pins at best. Speaking from experience here.
-Chris
Thanks for your reply. No, of course I don't want to use inferior parts. But when I looked for Augat sockets, they were ~$5.00 EACH!! That's outta my league---my machine is an 8-track, so we're talking 48 sockets here. The chips I want to use (LM4562)are only $1.11 each, so..... you really have used those exact ones from Phoenix Enterprises and found them to be junk? I know I have seen some "machined" sockets on eBay that were Chinee and looked horrible, much worse than the ones from PE.
A good compromise are the sockets from Mill-Max (referenced in a previous post) which are excellent quality and cost less than the op-amps in question.
110-43-308-41-001000 Mill-Max Manufacturing Corp. | Connectors, Interconnects | DigiKey
50 of these will run you $30.48
110-43-308-41-001000 Mill-Max Manufacturing Corp. | Connectors, Interconnects | DigiKey
50 of these will run you $30.48
Noted; good point. NOW I'm down to deciding between these Mill-Max parts:
110-47-308-41-001000 @ $0.336 (qnty 100)
110-43-308-41-001000 @ $0.583
The only difference I see is the contact (clip) on the more expensive part is "30µ Au" and the other is "Au flash"
So the question is, is it worth the $25 difference??
Hi dotneck335,
Yes, Millmax are also very good.
Gold is a soft metal that wears away very easily. The thicker coating will survive more IC changes than the flash type. If you aren't going to replace these ICs again, why are you even looking at sockets? If you are, why are you considering the flash type finish? It all comes down to a very easily answered question. In many locations, NE5532 would be fine. In low noise applications, LM4562 are the right answer (or OPA2134). You really only have a few locations where replacing the ICs might make any kind of reasonable difference.
LM4562 for 1.11 each? Did I miss something? Where? I'm going to get me some!
-Chris
Yes, Millmax are also very good.
Gold is a soft metal that wears away very easily. The thicker coating will survive more IC changes than the flash type. If you aren't going to replace these ICs again, why are you even looking at sockets? If you are, why are you considering the flash type finish? It all comes down to a very easily answered question. In many locations, NE5532 would be fine. In low noise applications, LM4562 are the right answer (or OPA2134). You really only have a few locations where replacing the ICs might make any kind of reasonable difference.
LM4562 for 1.11 each? Did I miss something? Where? I'm going to get me some!
-Chris
Hi Kevin,
I show them at $2.47 each, or $1.13226 for 2520 pieces. Canadian of course, so there is a substantial disadvantage where prices are concerned. What is the quantity for $1.11 each in USD?
-Chris
Edit, $4.04 each for LME49720P, $5.90 for your LME49860 in single quantity, surface mount only.
I show them at $2.47 each, or $1.13226 for 2520 pieces. Canadian of course, so there is a substantial disadvantage where prices are concerned. What is the quantity for $1.11 each in USD?
-Chris
Edit, $4.04 each for LME49720P, $5.90 for your LME49860 in single quantity, surface mount only.