Discussion in 'Marantz Audio' started by tensleep, Mar 30, 2017.
It came with the kit
Thanks. Did you just glue it on, or use some kind of double sided sticky tape, or what? Looking forward to seeing your final success pics!
I haven't secured it yet. I am deciding, but I think I will use some leftover speaker surround glue. I like the way it dries.
Double-sided tape is good to use and much easier to remove than glue. A craft store like Michael's has it. Search for "clear double sided tape 1/4""
48# vellum makes a nice diffuser. Here is where you can purchase the paper in small quantities for reasonable shipping:
Will probably be contacting you soon through your website about a 2230 cap kit for myself.
Goo Gone, microfiber towels, plastic clay shaping tools, hot soapy water and patience are talking good care of the old adhesive.
I found the plastic tools at Hobby Lobby while fruitlessly searching for 1/8" double sticky tape - I ended up ordering some from Amazon. These tools may also work well, scraping old adhesive from speaker baskets.
Now I have to wait for the tape to deliver.
FWIW ... I use double side carpet tape from Home Depot for all my units. You have to cut it to the desired width but it sticks exceptionally well ( and I do mean really well ) and the roll will last another 20 -30 units and I've done about 15 already with it. Oddly enough when I asked a tech friend of mine whose been an EE for 40 years what he used, he showed me the same roll of tape he uses on his restorations. I thought that kind of coincidental but thought if it's good enough for him...well. It has some sort of fibreglass threads that are imbedded in the tape that makes it really strong.
Hadn't thought about carpet tape. I had thought about cutting down some wider tape, but didn't feel like the hassle on this unit - it is taking forever as it is.
I will certainly file carpet tape away in the old memory banks - there are many uses for strong double sided tape.
My tape came in today - double sided 1/8". Hopefully tomorrow, I can get the face put back together and set the voltage levels.
After half a year, I am shooting to give this back to my friend this weekend.
Down to voltage levels!!
Stumped!! I forget where this brass nut goes.
Hmmmm I cannot seem to dial in the idle current. I can see that adjusting the trim pots have an effect on the dim bulb tester.
One channel will not go above 2.5 mV, and the other channel is all over the place, from 0-30mV. The proximity of my hand to the circuit and when I place it on the chassis has a big influence on this channel.
If I remember correctly it goes over the balance shaft and screws on , holding the faceplate in.
I now see the marks on the faceplate that confirm this.
I don't think it's recommended to set idle current on the DBT. If DBT dims properly, remove it and adjust idle current with volume at zero, balance centered and input on aux.
Will do and thx.
Crap! I mistakenly adjusted R760. What do I need to do to correct this? I do have a 5mV drop over R774 now.
EDIT: Ok, so there is a procedure in the service manual for setting the clipping on both channels; apparently, R760 balances the clipping level between both output transistors on each channel.
Well that's good !
R760 is the clipping balance adjustment. If it's adjustment is off, when the amp goes into clipping at 30 watts or more, it will clip the positive wave sooner than the negative wave, or the opposite.
What you can do when you have no oscilloscope is measure the DC voltage BEFORE the output coupling caps and use R760 to adjust the voltage there.
On the 1060 that voltage is 31 VDC. I'm not sure about the 2230, but they are similar amp-wise...
That 31 VDC is a bit less than half the main supply voltage, so if you measure your main cap DC voltage and adjust R760 so you see say 1 volt less than HALF that main cap voltage on the output cap, you're good to go.
Thanks Bert 1100. How does this look?
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