Luke said:
Hi Luke,
The SA7001 uses the same PCB as the SA8400, in other words: apart from the looks, they're identical! Here's a picture of the 7001, and here's the 8400. The 7001 indeed seems a cheaper replacement for the 8400. Sounds very nice, especially when modded
.Regards,
Ray
Yep, you could say that. I bought the 8400 anyway (second hand) because I like its looks better. A matter of taste of course, and they had to cut some costs on the 7001, so its looks are a bit more common. But they do come in a KI version 
. If I had a money-tree I would buy that one too and change the front and make my own SA8400-KI . That would be the ultimate mod!
These players respond very well to modifications, but so far the levels of change are not as big when compared to a 63 or 67 (I might get back on that, as i'm going to implement the discrete output PCB and a Flea clock soon: I hope it will be shocking). That would make sense, because these players are already at a higher level. The difference between a 63/67 and 8400 both out-of-the-box is night and day.
Regards,
Ray
. If I had a money-tree I would buy that one too and change the front and make my own SA8400-KI . That would be the ultimate mod!These players respond very well to modifications, but so far the levels of change are not as big when compared to a 63 or 67 (I might get back on that, as i'm going to implement the discrete output PCB and a Flea clock soon: I hope it will be shocking
). That would make sense, because these players are already at a higher level. The difference between a 63/67 and 8400 both out-of-the-box is night and day.Regards,
Ray
Regarding laser-unit:
i just swapped out the drive unit of my cd67 because the laser was quite old and i had trouble accessing cd-rs; after installing i noticed that the VAM1202 has even more trouble recognizing cd-rs!
It appears, those laser-units are of extreme poor quality, so my question: are there ANY other units of the VAM series that would be better, do they fit in anyway..?
regards,
mickie
i just swapped out the drive unit of my cd67 because the laser was quite old and i had trouble accessing cd-rs; after installing i noticed that the VAM1202 has even more trouble recognizing cd-rs!
It appears, those laser-units are of extreme poor quality, so my question: are there ANY other units of the VAM series that would be better, do they fit in anyway..?
regards,
mickie
mickie said:
Yeah it's more to with the RF/HF circuit than the laser.
The discrete CD63 circuit is better at tracking CD-R's.
I've confirmed this by swapping between the two.
I assume you mean what sometimes happens when you try to access a track directly and it 'hunts' for a few seconds then gives up?
The CD6000 also sometimes has this problem but that can be cured on the 6000. It has extra circuitry (hex inverters 'PC74HCU04D') to amplify the signal. The 67 and 6000 both use the TDA1302T RF amp but the 6000 uses it in 'low-gain' mode (so it can switch to 'high-gain' mode to read CD-RW). The 67 does not amp the signal and just works in high-gain mode. The 6000 fix is to put a 10pf cap on the 74HCU04 but we can't do that in our 67's because it doesn't have this.
In theory I do not see why you could not add this 'amp' to the 67 transport and select low-gain mode on the TDA1302T but that would be a bit of effort for something that may not work that well!
I found the problem depended on the brand of CD-R I used and the way I burned the disc. I now use 'Plextor' brand made by Taiyo Yuden (TY) and burn at 4x speed on my Plextor PX-755A using GigaRec 0.8 or 0.9 where possible. These settings trade disc capacity for larger 'pits' and 'lands' (ok so they are not really pits and lands on a CD-R) and makes them easier to read. Same principle as Yamaha's AMQR mode (I also have a CRW-3200E which has this). I use Exact Audio Copy to burn but I don't think that makes a difference.
Doing this I no longer have a problem.
Interestingly, in four years of use since I got my 67SE (used) it has NEVER ONCE skipped whilst playing a CD! NOT ONCE!
I have a VAM1202 in reserve for when it dies.
Hi Mickie,
Did you adjust the laser current yet? I just had the same problem with a modded CD57. The VAM units appear to do worse than the original ones...
I upped the laser current a bit, so the amplitude of the HF signal is now almost 2Vtt instead of the 1.7Vtt that's described in the service manual. This seems to solve the problem partially. The quality of the recorded disc is also important. Some disc are recorded so poorly that the HF signal is merely 1Vtt, and some still won't play.
Regards,
Ray
Did you adjust the laser current yet? I just had the same problem with a modded CD57. The VAM units appear to do worse than the original ones...
I upped the laser current a bit, so the amplitude of the HF signal is now almost 2Vtt instead of the 1.7Vtt that's described in the service manual. This seems to solve the problem partially. The quality of the recorded disc is also important. Some disc are recorded so poorly that the HF signal is merely 1Vtt, and some still won't play.
Regards,
Ray
Glenn2 / Ray, thanks for response; yes, the main Problem is finding a certain track in the middle of the cd-r: screeching and then stops.
I also use EAC to read and Yamaha AMQR to burn as well, using Mitsui CD-Rs, so thats not an issue i hope.
Even my old Rega Planet (sony KSS240A laser) used to access cd-r titles extremely fast and played even badly recorded ones....
At least i thought that was related to the laser....
Ray: How / where exactly do you adjust the laser...? Can i do it without a scope..?
mickie
I also use EAC to read and Yamaha AMQR to burn as well, using Mitsui CD-Rs, so thats not an issue i hope.
Even my old Rega Planet (sony KSS240A laser) used to access cd-r titles extremely fast and played even badly recorded ones....
At least i thought that was related to the laser....
Ray: How / where exactly do you adjust the laser...? Can i do it without a scope..?
mickie
No, you need a scope for that. You can monitor the HF signal at R105 (TP13) and adjust the current with the small trimpot that's on the flexfoil of the laserunit. If you remove the three screws that hold the transport and tilt it >90 degrees, you can easily reach the trimpot after you take out the drawer, without having to disconnect anything. Then pop the drawer back in and measure again to see the result of the adjustment.
Ray
Ray
Hi,
just a re-iteration of what I have seen on the web.
DVD writers can write data to CDr and CDrw with the correct pit and track spacing, but the pit width matches the high density, but narrow width, that is essential for DVD recordings.
This narrow pit width seriously reduces the reflections back into the receiver and causes reading problems.
Solution,
always use a CD writer to record to CDr and CDrw.
Don't know if this applies to any of the reported problems.
just a re-iteration of what I have seen on the web.
DVD writers can write data to CDr and CDrw with the correct pit and track spacing, but the pit width matches the high density, but narrow width, that is essential for DVD recordings.
This narrow pit width seriously reduces the reflections back into the receiver and causes reading problems.
Solution,
always use a CD writer to record to CDr and CDrw.
Don't know if this applies to any of the reported problems.
AndrewT said:
Hi Andrew/Mickie,
This is odd, as the discs on my Yamaha were much more affected than the ones done on my Plextor DVD burner.
In fact - since I switched to the DVD I don't think it has manifested itself at all.
On the Yamaha, sometimes AMQR is not an option because the disc being copied is >68 mins so you have to use normal DAO... these still exhibit the problem. When I do one on the Plex without GigaRec it's fine.
I've also never had a problem with discs I've burned on my work machine which has an LG combo drive (reads DVD but only burns CD).
I had an NEC ND-2510A briefly and discs burned on that are OK! (I always mark on the disc what I burned it with - I know, sad...)
Maybe it's just much more of a problem with Yamaha burns?
I remember seeing someone on audioasylum who had this problem on his 67 and he too had the Yamaha drive.
Soundwise, the Plex burns are as good if not better.
6h5c said:
Hi Ray,
I tried this on mine a few years back (both with the VAM1202 and the original CDM12.1 which I put back). It didn't seem to make a blind bit of difference! Though if you turn it up enough so the eye-pattern turns to $hit, it can play a CD-RW
Interesting what you say about the filter values - I might have a play with that!
Glenn
Hi Guys,
Just visited WAR Audio in Perth, Australia. Heard a great system based around his (Pat) Dianne speakers.
Pat modifies Pioneer DVD players and I asked him what a good nod would be to smooth the sound. He suggested a clock upgrade which I've done. I told him that I hadn't given it it's own power supply. He suggested using a battery.
He knows a guy who has multiple batteries to run different sections of his CD player.
I have a Trichord clock 3 and I think it has it's own regulator. If I buy a rechargable 6V battery and connected it to the two wires running from the clock, would that work OK?
Has anyone else tried it?
Thanks,
Simon
Just visited WAR Audio in Perth, Australia. Heard a great system based around his (Pat) Dianne speakers.
Pat modifies Pioneer DVD players and I asked him what a good nod would be to smooth the sound. He suggested a clock upgrade which I've done. I told him that I hadn't given it it's own power supply. He suggested using a battery.
He knows a guy who has multiple batteries to run different sections of his CD player.
I have a Trichord clock 3 and I think it has it's own regulator. If I buy a rechargable 6V battery and connected it to the two wires running from the clock, would that work OK?
Has anyone else tried it?
Thanks,
Simon
YoungSC said:
Hi Simon
Not tried batteries but read a little about them. I'd imagine a small battery will not have the required low imdedance to sound good. Thorsteon Loesch (iirc) described using batteries in a CD player as giving a grey, washed out sound. I think it depends how you go about it: what batteries you use and how you connect them.
Sealed lead acid batteries (often reffered to just as SLA) have low impedance. I think they're well suited to running a chip amplifier, as there have been various positive reports. The noise is comparable with a mediocre regulator (but not as low noise as a "super" regulator). This was measured by Andrew Leakes (designer of the ALW super reg). From what I've read I'd say a battery system may sound better than a poor AC-powered setup, but the very best will be mains powered (and less bulky, messy and inconvenient). I think these are the reasons most people don't bother with batteries.
Why not try it on your clock though, see how it compares. It will at least be isolated from the other circuits.
In other news: I just ate a caramel shortbread with virtually no shortbread at the bottom
Simon
Simon, eat too many of them and u wont be able to get up to change CD's, then youll have to have one of those 100 multi cd changer things LOL
Its a half calorie mince pie Christmas for me (not eating twice as many as last year !!!)
The other Simon, i wouldnt recommend using a 6volt battery if the clock uses any TTL devices, as you will exceed the max voltage for the supply to the chips and possibly the oscillator if it uses one ? You shouldnt power TTL beyond 5.25 volts normally, there are soem exceptions i believe tho.
Merry Christmas, hope Santa brings you all the CD's you wanted !
Dennis
Its a half calorie mince pie Christmas for me (not eating twice as many as last year !!!)
The other Simon, i wouldnt recommend using a 6volt battery if the clock uses any TTL devices, as you will exceed the max voltage for the supply to the chips and possibly the oscillator if it uses one ? You shouldnt power TTL beyond 5.25 volts normally, there are soem exceptions i believe tho.
Merry Christmas, hope Santa brings you all the CD's you wanted !
Dennis
