By mistake I ordered a 2X18V Tx
Open circuit no load voltage is 30V and when loaded working voltage is 25-26V.
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I am planning to mod a 2nd CD63 after completion of the fist one (which I am still waiting for the Fleas). I will not make the same mistake againNow will you cave into peer pressure and get some smaller 25v caps?
Try this one and it should work. The dia. should be somewhere around 35mm.
36 mm. DIAMETER RUBBER DRIVE BELT FOR CASSETTE DECKS | eBay
Yes, that would be a good alternative. If you still want something cheaper try this:
AUDIO/CASSETTE SQUARE SECTION DRIVE BELT. 35mm x 1.2mm (1 BELT) | eBay
It should be as GOOD as the others
Couple of questions for the guys with multiple transformers:
I've asked this before, but do you hear any mains hum in stop mode with the volume maxed? I used to hear just the residual DAC noise, but now there's mains hum mixed in with that. I wonder if I have a 'dirty chassis' (a term I picked up investigating ground problems on audio equipment).
230v guys: If you buy a transformer with 2x115v primaries, how do you parallel the primaries? Do you tend to cut the wires shorter first?
Thanks,
Ben
I've asked this before, but do you hear any mains hum in stop mode with the volume maxed? I used to hear just the residual DAC noise, but now there's mains hum mixed in with that. I wonder if I have a 'dirty chassis' (a term I picked up investigating ground problems on audio equipment).
230v guys: If you buy a transformer with 2x115v primaries, how do you parallel the primaries? Do you tend to cut the wires shorter first?
Thanks,
Ben
No mains hum whatsoever on my multiple transformer 67. First of all I'm no expert on these things but I would check the grounding scheme first and then check to see if the mains hum is caused by mains wiring being in the proximity of signal wiring. all my mains wiring is routed tight to the outside of the case. One last thing to check, put scope on the analogue power rails to see if mains noise is present there.
As for the 2x115v primaries, you wire them in series. I personally don't cut the wires short just in case I want to change anything or reuse the transformer.
As for the 2x115v primaries, you wire them in series. I personally don't cut the wires short just in case I want to change anything or reuse the transformer.
Hi all been a while since i have been on here. Im after some help with my marrantz 67se its had some mods done its had the hdam circuit by passed it as a n external power supply but not sure what it runs i repaced the opamps with the ha screened ones, But it sounds bright and harsh with not much bottom end clout. And just wondered if there was any one in sheffield who could have a look at it and make sure its been done right
Hi Ben. I have 3 Txs in my CD63 and I don't have 50Hz hum. When I crank the amp. to full power I can only hear a very slight hizzing sound from the speaker tweeter and there is no hum at all.
for the primary you should connect like this to get 230V:
_________
{
{ 115V
{__________
__________) joint these
{
{ 115V
{__________
You may cut short the middle cables before you join them together and then insulated the connections if you are not going to connect to 115V supply in future.
Not sure i have done nothing only changed the opamps as electronics is not one of my strong points lol. I could post a pic of the board some regulaters have been changed and some big caps put on the voltage input but the work looks shabby to me and untidy. Just wondering if the person who did it knew what he was doing
Thanks for your replies, folks. It seems I have my transformers wired correctly, and all my mains cables are northwest of the original transformer position so unlikely to interfere. I'll double check that the smoothing caps on the analogue rails are soldered properly, then it might be time to think about getting a scope.
I'd say so.
A scope, even an old one (mine is an old fluke portable job), is near essential. My CD67 would still be sitting there clicking with the disc spinning in the wrong direction without one.
Hi Ben
I got some mains hum on mine many years ago and it was because of the location of the analogue stage psu to the transformer. I could not get rid of it. Once I built an external psu for the output stage the hum went away (obviously). Run +/- voltage into the player and direct to your output stage, if you build a good psu you will also get audio improvements.
Also doing this frees up a area for a tx to be used for other circuits
Brent
Ok done it this is whats been done i have only upgraded the opamps rest was done when i bought the player. Detail is not bad but trebble is harsh and bass is not as deep as i would like the midrange is not so good eather. I have had a moded 67se before and i know what thay can sound like but this one does not do it