Melos GK-1+1 Preamp ... second call
- Thread starter lorne
- Start date
Blue Shadow
Waiting for Vintage Gear from this century
It appears from the info on the schematic you can determine what the dip switches do as far as resistance and what appears to be capacitance and then calculate what the different switch positions would yield. Easier to have the manual say "chinacave, for your cartridge set the dip switches to one up, two down, three down four up and for the second set use 1-3 up and 4 down." But you could determine what the resulting values are for different settings and dial in your cartridge based on recommended starting points.
Hi Melos fans. It's been some time; I've been distracted by other concerns.
What I should do is take a bunch of photos and find my notes. I cannot do this for a few days at least because by son has taken the camera to Kyushu on a school trip. Thanks to Ian for the "heads-up" in regards to the recent activity on this thread.
What I should do is take a bunch of photos and find my notes. I cannot do this for a few days at least because by son has taken the camera to Kyushu on a school trip. Thanks to Ian for the "heads-up" in regards to the recent activity on this thread.
chinacave
Its Like a Jungle Sometimes; It makes me Wonder
Two things -
one - am I correct in thinking that the two dip switches per channel are the ones on the schematic labeled "loading' and 'gain'?
two - for some as yet unknown reason, one channel is out and the other very faint on my unit. I did remove a turntable the other day, and then my lady got home before me and turned on the stereo, discovering the issue, so I will have an opportunity to compare the schematic to the unit I have in trying to troubleshoot....
one - am I correct in thinking that the two dip switches per channel are the ones on the schematic labeled "loading' and 'gain'?
two - for some as yet unknown reason, one channel is out and the other very faint on my unit. I did remove a turntable the other day, and then my lady got home before me and turned on the stereo, discovering the issue, so I will have an opportunity to compare the schematic to the unit I have in trying to troubleshoot....
Thanks a ton for passing along the two sheets from Melos - I had faxed copies of the same, but they were impossible to read.
FYI, even Mark Porzilli, the original designer, does not have any access to the actual owner's manual, so if you have a copy that you'd be willing to post, or to photocopy for me, I'd be eternally grateful! Thanks in advance,
Tim (reverend_tim@msn.com)
FYI, even Mark Porzilli, the original designer, does not have any access to the actual owner's manual, so if you have a copy that you'd be willing to post, or to photocopy for me, I'd be eternally grateful! Thanks in advance,
Tim (reverend_tim@msn.com)
mdye
Active Member
I've recently obtained an early version of the Melos GK-1 (small PSU enclosure, single power transformer, P2P wiring in the PSU) with a noisy power transformer. Has anyone discovered a drop in replacement (or close to) for those trannies? Anyone know what the exact voltages coming out of the secondaries should be? Just want to confirm how bad off this transformer actually is.
I just noticed this post you made about three months ago. So I thought I'd help you trace down some info in case you did not get there yourself — and anyone else following up behind.
The lack of any real, solid documentation on these old preamps makes for some confusion. Various versions and revisions made by the Melos lab/factory, as well as field modifications make things all the more confusing. But, careful scrutiny of information contributed by various members over the years can be very helpful.
I think you will get some use out of this link that goes to another thread here on Audio Karma. It includes my copy of the owner's manual, such as it is. Also, there are some drawings and photos I made showing how I rebuilt the frying power supply unit. Other members have supplied some other docs, including a schematic of one GK version. In addition, there are notes on various parts, and the tube complements that were not always the same and varied between the original GK, the GK-1 and the GK 1+1. Some GK-1's were retro-fitted (by Melos) and became GK 1+1's, despite what might have been printed or stencilled on the face or the rear panel. I'll leave that for you to figure out
)))My current interest is trying to identify what sort sorts of capacitors are on the preamp and phono board. Some are pretty exotic and unmarked. Each type poses the question as to what would be a good, modern replacement. Considering the age of these pieces, it seems only wise to be thinking ahead. Thirty years is a long time for many capacitors
Anyway, see here: http://audiokarma.org/forums/index.php?threads/melos-gk-1-1-docs.617261/
EDITED: I just noted that a lot of the images cited above are obscured by Photobucket watermarks. Whe I get time, I will repost the images and add a lot of stuff from my notebooks in regards to the rebuilt of the "long" twin Xformer version of the power supply.
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