Beeger-
I've ordered the Panasonic caps. I'm going to put the Blackgates in one and Panasonic in the other and compare.
You're right about finding the 1000uF power supply caps with axial leads.... the ones I've found so far are fairly generic; would that be OK in this application?
Thanks again.
Kirk
I've ordered the Panasonic caps. I'm going to put the Blackgates in one and Panasonic in the other and compare.
You're right about finding the 1000uF power supply caps with axial leads.... the ones I've found so far are fairly generic; would that be OK in this application?
Thanks again.
Kirk
Kirk57: Yes, generic is good, but that is why I suggested you might want to upsize them a bit. A 40-50 Volt cap at around 1500-2000 should still fit if the diameter doesn't get too big. We're looking for low ESR here and that comes with size and Voltage in generic brands as well as specialty types. You might even consider a higher Amperage diode bridge, or two if your units are dual monos. There are some compact six Amp devices available that can be installed in the original board with a little care.
Hey, after twenty years, why not go for broke?
Hey, after twenty years, why not go for broke?
Beeger-
OK I now have the Panasonic caps as well as the Blackgates.
How would you recommend getting the boards out to replace the caps? Maybe taking all the swithces and pots off the front?
Not much room to move around in there...
These are Revelation dual monos BTW (the small black ones) SNs 1270 and 1291.
Thanks again
Kirk
OK I now have the Panasonic caps as well as the Blackgates.
How would you recommend getting the boards out to replace the caps? Maybe taking all the swithces and pots off the front?
Not much room to move around in there...
These are Revelation dual monos BTW (the small black ones) SNs 1270 and 1291.
Thanks again
Kirk
Kirk57: Did I mention that you don't get the boards out? Tiny, highly trained urchins will be needed to work under the boards...good luck with that. Seriously, you unsolder the phono wires and the wires from the board to the selector switch. You can put a labeled bit of tape on each wire or draw a diagram if you want to be certain of correct replacement. There are two mounting screws holding the board. One in the middle front and one in the middle back. Remove the nuts from those and the board will lift up far enough to unsolder the short ground wire from the bottom/rear of the board. That will allow the board to be elevated enough to access the underside. It may look confusing at first, but stare at it long enough and I'm sure the dawn of enlightenment will shine upon you. It's a worthy mission and the force will be with you.
The trained urchins have put the new caps in
I works! But I'm noticing is that when switched to phono input, the first set of caps on the main board (closest to the input) seem
*very* sensitive to hum, when I put my hand near them definite hum is heard, and I can hear the input from the tuner at a low level - behaviour is the same on both channels.
Also when I tap the top very loud pop is heard, but maybe I shouldn't be tapping them....
Cold solder joints? any other ideas?
I works! But I'm noticing is that when switched to phono input, the first set of caps on the main board (closest to the input) seem
*very* sensitive to hum, when I put my hand near them definite hum is heard, and I can hear the input from the tuner at a low level - behaviour is the same on both channels.
Also when I tap the top very loud pop is heard, but maybe I shouldn't be tapping them....
Cold solder joints? any other ideas?
Kirk57; My best guess is that there is nothing in the phono jacks. The phono input has very high gain and is designed to be loaded by less than 2 kOhms to ground. If the sockets are empty, it will be very sensitive to stray hum pickup. As for the effects when the turntable is connected, if they are still there then there may be another problem. Or, it could just be caps that are very microphonic. It's rare, but it does happen. Also, are you sure you got the hot and ground input wires back on correctly? Switching these will make for some interesting phenomena too. I do all post modification tests with either a generator or shorting plugs in the phono inputs. As for the microphonic caps, you could try replacing them or putting some damping putty or other material on them. Whatever works is good.
Looks like this may be a grounding problem. If I touch the chassis the problem is gone...need to investigate more
BTW do you put any stock in the replacement power cord thing?
I'm thinking about putting an EIC socket on the power supply, maybe running thicker cable between PS and the Pre-amp.
Think this is worth doing?
BTW do you put any stock in the replacement power cord thing?
I'm thinking about putting an EIC socket on the power supply, maybe running thicker cable between PS and the Pre-amp.
Think this is worth doing?
Kirk57; Regarding the hum problem: Did you remember to reattach the short ground wire on the bottom of the board? That would certainly account for some hum problems.
Yes, an IEC socket would permit the use of a heavier power cord. Some sound quite a bit better than the average computer or extension cord. You could even experiment with your own recipe at Home Depot for quality wire and low prices. About the biggest wire that will fit into the chassis is sixteen gauge/three conductor. You can probably find that at your builder's supply as well. You may need to open the chassis hole a bit and get a new strain relief to fit the bigger wire. While you are on your quest for lower source impedance from the power supply, I would remind you about using bigger diode bridges on the power supply board. The original bridges will become the limit to further progress.
Next you'll be asking about bigger transformers!
Yes, an IEC socket would permit the use of a heavier power cord. Some sound quite a bit better than the average computer or extension cord. You could even experiment with your own recipe at Home Depot for quality wire and low prices. About the biggest wire that will fit into the chassis is sixteen gauge/three conductor. You can probably find that at your builder's supply as well. You may need to open the chassis hole a bit and get a new strain relief to fit the bigger wire. While you are on your quest for lower source impedance from the power supply, I would remind you about using bigger diode bridges on the power supply board. The original bridges will become the limit to further progress.
Next you'll be asking about bigger transformers!
Beeger-
Yep, the hum problem was just a loose ground. I have the preamp back in the system and starting the break-in process.
I know the Blackgates tookat least 50 hours (some say a lot more) so I'll give these a week or so. Right now kinda bright, but as I recall the Blackgates were bright at first too.
Regarding the EIC cords: do you think this is worth doing?
Regarding the Diode Bridges: What do they look like? Are those the ones called out as 2N2222A and 1N4484 on the schematic? Looks like there are 10 altogether?
Regarding the transformers: Is there a problem with the transformers???
Yep, the hum problem was just a loose ground. I have the preamp back in the system and starting the break-in process.
I know the Blackgates tookat least 50 hours (some say a lot more) so I'll give these a week or so. Right now kinda bright, but as I recall the Blackgates were bright at first too.
Regarding the EIC cords: do you think this is worth doing?
Regarding the Diode Bridges: What do they look like? Are those the ones called out as 2N2222A and 1N4484 on the schematic? Looks like there are 10 altogether?
Regarding the transformers: Is there a problem with the transformers???
Kirk57; Glad to hear about the hum cure. Many electrolytic caps are thin and bright sounding until they form up properly. You can find graphs showing leakage vs time with voltage applied from most cap manufacturers. Many manufacturers will not guarantee the caps meet spec until 80% of rated voltage has been applied for 1000 hours! Fortunately, the ESR/leakage curve is a reverse exponential one with the most dramatic changes occurring in the first 100 hours.
The IEC socket will permit you to try different power cords, many of which you can make for yourself. I think Parts Express even offers a kit of male and female connectors for such a project. That cord is from the wall to the power supply box. The other (16 Ga.) wire I was referring to is from the box to the preamp.
Your question regarding the diode bridges indicates to me that you should not try to change them yourself. FYI, the bridges look like little round 'buttons' and are between the large caps on the regulator board. Each one has four legs going down into the board. Two of the legs are for the incoming AC and the other two are for + and - voltage respectively. It is imperative that any bigger ones be installed correctly or the results will be unpleasant. If you know anyone who could assist you with the project it will be worth doing. Alternatively, you could embark on a program of self education and study information available on the internet from manufacturers and hobby forums. There's a lot out there, and some of it is true! Here is an example:
http://en.wikipedia.org/wiki/Diode_bridge
The small round unit is similar to the ones in your preamp. The middle sized, rectangular one would be the size I had in mind for the upgrade. Medium sized bridges are also available in square packages which have the same pin pattern as the little round ones but are higher amperage.
There is no 'problem' with the transformer. However, a bigger one does improve the sonics. That should probably come after the diode project in order of significance.
The IEC socket will permit you to try different power cords, many of which you can make for yourself. I think Parts Express even offers a kit of male and female connectors for such a project. That cord is from the wall to the power supply box. The other (16 Ga.) wire I was referring to is from the box to the preamp.
Your question regarding the diode bridges indicates to me that you should not try to change them yourself. FYI, the bridges look like little round 'buttons' and are between the large caps on the regulator board. Each one has four legs going down into the board. Two of the legs are for the incoming AC and the other two are for + and - voltage respectively. It is imperative that any bigger ones be installed correctly or the results will be unpleasant. If you know anyone who could assist you with the project it will be worth doing. Alternatively, you could embark on a program of self education and study information available on the internet from manufacturers and hobby forums. There's a lot out there, and some of it is true! Here is an example:
http://en.wikipedia.org/wiki/Diode_bridge
The small round unit is similar to the ones in your preamp. The middle sized, rectangular one would be the size I had in mind for the upgrade. Medium sized bridges are also available in square packages which have the same pin pattern as the little round ones but are higher amperage.
There is no 'problem' with the transformer. However, a bigger one does improve the sonics. That should probably come after the diode project in order of significance.
Beeger-
After some hours of burn in the preamp is sounding very nice indeed, hearing lots of soundstage events outside of the speakers, tonal balance very much to my liking.
Regarding the rectifiers, I should have Googled that before asking the question
; these look like smaller versions of the rectifiers I installed on a tube amp this summer.
I've downloaded the spec sheet RB150 spec sheet; I see you've suggested 4-6 amp as as opposed to the RB150's 1.5. Anything else I should look for, apart from correct voltage, and getting ones that actually fit?
Kirk
After some hours of burn in the preamp is sounding very nice indeed, hearing lots of soundstage events outside of the speakers, tonal balance very much to my liking.
Regarding the rectifiers, I should have Googled that before asking the question
; these look like smaller versions of the rectifiers I installed on a tube amp this summer.I've downloaded the spec sheet RB150 spec sheet; I see you've suggested 4-6 amp as as opposed to the RB150's 1.5. Anything else I should look for, apart from correct voltage, and getting ones that actually fit?
Kirk
Kirk57; No, a minimum peak reverse voltage of 100 volts should do it. The other item for you wish list is the pin out, as I mentioned before. It makes the conversion a little easier. The small pattern square ones should do nicely. If 200 volt PIV bridges are available you can use them as well. You can always go higher, just not lower than 100 PIV.
superphon revelation 2 pre-amp
Hi yeoldestereo saw your posts and have chatted with you on Audiogon but can't remember the details. Maybe I purchased from you.
Just bought a superphon rev 2 pre and WOW what an change in my sound. Replaced an audire pre and and using an audire amp with coincident troubadours.(just need the dang troubass to complete but can't find anyone willing to sell them). May have to have some made.
Getting ready to replace the connectors and have heard it will take it to a higher level.
Do you still have yours? I have seen on some other forums many people who have and enjoy the superphon but need schematics. I have the manual with both phono and line available and will be happy to fax or mail them at no charge.
Of course I can tell by reading your posts that you do not need them.
Happy listening.
Lori
Hi yeoldestereo saw your posts and have chatted with you on Audiogon but can't remember the details. Maybe I purchased from you.
Just bought a superphon rev 2 pre and WOW what an change in my sound. Replaced an audire pre and and using an audire amp with coincident troubadours.(just need the dang troubass to complete but can't find anyone willing to sell them). May have to have some made.
Getting ready to replace the connectors and have heard it will take it to a higher level.
Do you still have yours? I have seen on some other forums many people who have and enjoy the superphon but need schematics. I have the manual with both phono and line available and will be happy to fax or mail them at no charge.
Of course I can tell by reading your posts that you do not need them.
Happy listening.
Lori
Beegar you must be the designer of this pre-amp and if so it would be great to be able to get in touch with you.
Love the revelation and would like to stay in touch in case I need assistance in the future.
If you are not the designer you are still a great source of info and ditto the previous line.
Thanks!
Love the revelation and would like to stay in touch in case I need assistance in the future.
If you are not the designer you are still a great source of info and ditto the previous line.
Thanks!
Horsnit: No problem. Let me know if you have any issues or questions regarding the Revelation II or the original Revelation basic. Both have room for significant upgrades and most of those are relatively inexpensive to do if one is handy with a soldering iron and has a bit of experience. As always, it's a good idea to block out some time when you won't be disturbed before starting the surgery . Forgetting where you left off or skipping a step is the most common cause of modification mishaps and good intentions gone wrong.
Regards,
Beeger
. Forgetting where you left off or skipping a step is the most common cause of modification mishaps and good intentions gone wrong.Regards,
Beeger
Horsnit: No problem. Let me know if you have any issues or questions regarding the Revelation II or the original Revelation basic. Both have room for significant upgrades and most of those are relatively inexpensive to do if one is handy with a soldering iron and has a bit of experience. As always, it's a good idea to block out some time when you won't be disturbed before starting the surgery
Regards,
Beeger
Hello Beeger,
I have the Basic Revelation - it's still with my service technician, since I don't have the schematic for it, and neither does he. Any idea where it could be found please?
Your help is greatly appreciated!
Regards
Peter
Finally after all these years taking the plunge
Hi, thanks Guild for your post.
Well I just purchased ELNA SILMIC II 50V 100 UF radial caps and 4 VISHAY 40V 1000 uf axial caps. The SILMIC II were judged better than either the Panasonic or the Blackgate caps @ Comparing electrolytic capacitors - May 2008 at high end audio by Eric Juaneda, and form other things I have read on the net, the SILMIC II seems like a great choice. I got the VISHAY 40V 1000 uf axial caps because this is about the only axial cap I could find that was the right size peroid, they go on the power supply side so just replacing them because of age at Beegers sugestion.
I also just purchased 2, 10k mono 24 stepped Attenuators to replace the volume pots. I got them cheap out of Hong Kong, off ebay
I also have some solid silver hook up wire that i will use to replace some of the more important internal wires.
I was thinking about by-passing the mute switch entirely, what are your thoughts on this idea? Just go directly from the Audio board to the line out jack.
I was also thinking of replacing the 2, diode bridges with 6A 6 Amp 600V Bridge Rectifier GBPC606, Manufacturer: General Semiconductor
</B>Part Number: GBBC606 THIS IS THE LITTLE SQUARE ONE,
what is so hare about replacing these? i don't have any experience replacing anything on a circut board, but a electricion friend of mine from work is going to help me.
Next what size of transformer should i get to replace the one in the power supply box?
These mods are the ones mentioned here in this thread, are there any others i need to consider?
maybe the change the output jacks? and ?
Thank for help
Ron
Hi, thanks Guild for your post.
Well I just purchased ELNA SILMIC II 50V 100 UF radial caps and 4 VISHAY 40V 1000 uf axial caps. The SILMIC II were judged better than either the Panasonic or the Blackgate caps @ Comparing electrolytic capacitors - May 2008 at high end audio by Eric Juaneda, and form other things I have read on the net, the SILMIC II seems like a great choice. I got the VISHAY 40V 1000 uf axial caps because this is about the only axial cap I could find that was the right size peroid, they go on the power supply side so just replacing them because of age at Beegers sugestion.
I also just purchased 2, 10k mono 24 stepped Attenuators to replace the volume pots. I got them cheap out of Hong Kong, off ebay
I also have some solid silver hook up wire that i will use to replace some of the more important internal wires.
I was thinking about by-passing the mute switch entirely, what are your thoughts on this idea? Just go directly from the Audio board to the line out jack.
I was also thinking of replacing the 2, diode bridges with 6A 6 Amp 600V Bridge Rectifier GBPC606, Manufacturer: General Semiconductor
</B>Part Number: GBBC606 THIS IS THE LITTLE SQUARE ONE,
what is so hare about replacing these? i don't have any experience replacing anything on a circut board, but a electricion friend of mine from work is going to help me.
Next what size of transformer should i get to replace the one in the power supply box?
These mods are the ones mentioned here in this thread, are there any others i need to consider?
maybe the change the output jacks? and ?
Thank for help
Ron