Thankyou
SA-7.
Hi,
The SA-7 has indeed a dual 100K pot from ALPS.
A stepped L-attenuator would be a great improvement but I don't think there's all that much space to fit it inside.
If you want to upgrade this unit I would recommend trashing the Wondercraps and putting in some high-Q polyprops or styrenes instead.
MIT Multicap would be my preferred choice.
The resistors are mostly Resistas from Roederstein and Dale,these should be fine.
This preamp suffers from microphony though,so you will want to isolate it from floor and airborne vibes.
Cheers,
Hi,
The SA-7 has indeed a dual 100K pot from ALPS.
A stepped L-attenuator would be a great improvement but I don't think there's all that much space to fit it inside.
If you want to upgrade this unit I would recommend trashing the Wondercraps and putting in some high-Q polyprops or styrenes instead.
MIT Multicap would be my preferred choice.
The resistors are mostly Resistas from Roederstein and Dale,these should be fine.
This preamp suffers from microphony though,so you will want to isolate it from floor and airborne vibes.
Cheers,
YOU WONDER?
Hi,
I can't type properly...
Correct.
Fortunately there aren't all that many caps to upgrade and even the MIT popyprops would be a nice upgrade already.
From memory,I think the original ones were rated at 200-250 V so that would be O.K size-wise.
Some drilling on the PCB will be necessary to pass the thick leadout wires of the MITs though.
So careful before you short some traces on that soundboard...err...PCB.
Cheers,
Hi,
I can't type properly...
Correct.
Fortunately there aren't all that many caps to upgrade and even the MIT popyprops would be a nice upgrade already.
From memory,I think the original ones were rated at 200-250 V so that would be O.K size-wise.
Some drilling on the PCB will be necessary to pass the thick leadout wires of the MITs though.
So careful before you short some traces on that soundboard...err...PCB.
Cheers,
Re: Re: Soundboard!!
Hi,
Not sure if your question is serious or not, but it relates to post #6 in the "Listening tests" thread.
Whether I bored a thousand readers or not, I did spend over 30 mins, late at night, trying to offer some helpful advice, whereas most of what this poster had already said was rather negative, and of no practical help to a 'novice', at all. It appears that the originator of the thread found my comments interesting, anyway.
Incidentally, I appreciated your post # 54 in "The Silly Question" thread, a point (one of many!) which I had also noticed amongst the efforts to discredit my comments, but, as with all the other incorrect remarks, it wasn't worth my time in referring to it.
I was interested in your own experiences about casting as I have done some of this (a long while ago), especially of the 'lost wax' variety. This was when I worked in the silver/jewellery trade, and I found it fascinating.
Am I right in assuming that this is an interest of yours, rather than your means of livelihood?
Regards,
Sch3mat1c said:
Wot's all dis den?
Tim (Deputy of the Apostrophe Police on alt.binaries.schematics.electronics
Hi,
Not sure if your question is serious or not, but it relates to post #6 in the "Listening tests" thread.
Whether I bored a thousand readers or not, I did spend over 30 mins, late at night, trying to offer some helpful advice, whereas most of what this poster had already said was rather negative, and of no practical help to a 'novice', at all. It appears that the originator of the thread found my comments interesting, anyway.
Incidentally, I appreciated your post # 54 in "The Silly Question" thread, a point (one of many!) which I had also noticed amongst the efforts to discredit my comments, but, as with all the other incorrect remarks, it wasn't worth my time in referring to it.
I was interested in your own experiences about casting as I have done some of this (a long while ago), especially of the 'lost wax' variety. This was when I worked in the silver/jewellery trade, and I found it fascinating.
Am I right in assuming that this is an interest of yours, rather than your means of livelihood?
Regards,
Hi to everybody(great imfo)thanks+
Hi,Thankyou to all of the people who posted some great imfo regarding the counterpoint sa-7 pre amp that i have.
The value pot ratings are very usefull, Also the the cappacitor issue.
I had the idea of replacing the volume control after reading many hi-fi magazines articles and also noticing the differnce one made when i had an Audio research pre amp.I have seen some very cool Alps pots from Japan at £300+
These look awsome and apparently sound fantastick.
I believe that counterpoint volume pots were pretty basic in the early desighns.
One are that i have yet to try is running a pre amp on batteries instead of the mains outlet. I have seen maplin electronics sell small heavy duty motorcycle batteries that can be recharged,I believe that Unison research did a valve pre amp that had small watch batteries that heated the valve elements.
I think that this technology is not exploited enough
Thanks also for the issue of michrophony in this pre amp,I have got some valve rings which i will place on the valves,Manybe there are many other options to cater for this sort of thing
Thankyou fellow audiophiles
Ian.
Hi,Thankyou to all of the people who posted some great imfo regarding the counterpoint sa-7 pre amp that i have.
The value pot ratings are very usefull, Also the the cappacitor issue.
I had the idea of replacing the volume control after reading many hi-fi magazines articles and also noticing the differnce one made when i had an Audio research pre amp.I have seen some very cool Alps pots from Japan at £300+
These look awsome and apparently sound fantastick.I believe that counterpoint volume pots were pretty basic in the early desighns.
One are that i have yet to try is running a pre amp on batteries instead of the mains outlet.
I have seen maplin electronics sell small heavy duty motorcycle batteries that can be recharged,I believe that Unison research did a valve pre amp that had small watch batteries that heated the valve elements. I think that this technology is not exploited enough
Thanks also for the issue of michrophony in this pre amp,I have got some valve rings which i will place on the valves,Manybe there are many other options to cater for this sort of thing
Thankyou fellow audiophiles
Ian.
KONTRA PUNKT.
Hi,
300 quid for a couple of pots??.
For that kind of money half a dozen of top notch stepped attenuators can be made/bought.
Personally I wouldn't spend too much money on a SA-7, it was a midrange product from CP and no matter how cash you care to throw at it, nothing is going to change that.
Be aware that batteries don't last all that long and that they constantly will discharge while you have the unit on.
The heaters consume the lion share and sonically benefit the least.
Cheers,
Hi,
300 quid for a couple of pots??.
For that kind of money half a dozen of top notch stepped attenuators can be made/bought.
Personally I wouldn't spend too much money on a SA-7, it was a midrange product from CP and no matter how cash you care to throw at it, nothing is going to change that.
Be aware that batteries don't last all that long and that they constantly will discharge while you have the unit on.
The heaters consume the lion share and sonically benefit the least.
Cheers,
Thamks Frank
Hi Frank,
Thanks for the superb reply,
Will deffinatly bear this in mind for the sa-7.
I had bought it from Ebay and was intending on moddding it for my uncle who is new to high end audio and lives in the usa.
Batterys do look good on paper but i hadnt realised there shortcomings Frank,I had seen a pre amp from Nagra that has some built in.
One Counterpoint pre amp i have seen is the sa-11,ssooooo many valves
The Alps pots are expensive,Have also seen Danish stepped ct-1 but never had one before.
I suppose that the cap replacement etc will bring the most differences,
THX Frank
Ian.
Hi Frank,
Thanks for the superb reply,
Will deffinatly bear this in mind for the sa-7.
I had bought it from Ebay and was intending on moddding it for my uncle who is new to high end audio and lives in the usa.
Batterys do look good on paper but i hadnt realised there shortcomings Frank,I had seen a pre amp from Nagra that has some built in.
One Counterpoint pre amp i have seen is the sa-11,ssooooo many valves
The Alps pots are expensive,Have also seen Danish stepped ct-1 but never had one before.
I suppose that the cap replacement etc will bring the most differences,
THX Frank
Ian.
Re: KONTRA PUNKT.
Be aware that batteries don't last all that long and that they constantly will discharge while you have the unit on.
The heaters consume the lion share and sonically benefit the least.
Cheers, [/B][/QUOTE]
Hi Ian,
It is good to see some appreciative comments from someone, and I bet Frank is pleased with those, as it makes the effort worthwhile. There are far too many folk around who spend their time trying to argue or discredit what others have said, and most of them probably don't know much about the subject, anyway!
You can rely on what he has to say about valves, as he clearly knows his stuff here.
I had one of your pre-amps for repair once, and it wasn't bad-sounding, but like Frank said, it is doubtful if spending £300 in that way would be very cost-effective.
On the subject of batteries, I am not a valve man, and the only *audio* valve amp I ever made, I subsequently gave away, and I don't now recall the current requirements.
However, on my (remaining!) DIY valve guitar amp (only 2 watts output, so probably not too far different in current draw from a pre-amp) it draws 1.3 amps continuously for the heaters.
Going back to what you said about using watch batteries which normally range from about 30 mAh, to 100 mAh, at that rate I reckon a watch battery would last from between just over one minute to about five minutes, so you would need an awful lot of them!
I live quite close to you, incidentally, in Shakespeare country.
Regards,
Be aware that batteries don't last all that long and that they constantly will discharge while you have the unit on.
The heaters consume the lion share and sonically benefit the least.
Cheers,
[/B][/QUOTE]Hi Ian,
It is good to see some appreciative comments from someone, and I bet Frank is pleased with those, as it makes the effort worthwhile. There are far too many folk around who spend their time trying to argue or discredit what others have said, and most of them probably don't know much about the subject, anyway!
You can rely on what he has to say about valves, as he clearly knows his stuff here.
I had one of your pre-amps for repair once, and it wasn't bad-sounding, but like Frank said, it is doubtful if spending £300 in that way would be very cost-effective.
On the subject of batteries, I am not a valve man, and the only *audio* valve amp I ever made, I subsequently gave away, and I don't now recall the current requirements.
However, on my (remaining!) DIY valve guitar amp (only 2 watts output, so probably not too far different in current draw from a pre-amp) it draws 1.3 amps continuously for the heaters.
Going back to what you said about using watch batteries which normally range from about 30 mAh, to 100 mAh, at that rate I reckon a watch battery would last from between just over one minute to about five minutes, so you would need an awful lot of them!
I live quite close to you, incidentally, in Shakespeare country.
Regards,
Hi,Thankyou for the great imfo
Hi to everybody at Audio.com.
I have read all of the replys to my query and am very greatfull for all of the advice.
Please accept my appologies for not replying lately as i have managed to catch a horrible British cold and have beebn flued up for over a week.I dont normally get the flu but the weather here in England has been miserable lately.
Thankyou to the previous reply,Its great to hear from you in Shakespear land("BUEATIFULL COUNTRYSIDE") and many thanks for your comments. I have printed all of the imfo and will deffinatly post a thread later on today.
Have to just go and take some more medicane.......THX
Hi to everybody at Audio.com.
I have read all of the replys to my query and am very greatfull for all of the advice.
Please accept my appologies for not replying lately as i have managed to catch a horrible British cold and have beebn flued up for over a week.I dont normally get the flu but the weather here in England has been miserable lately.
Thankyou to the previous reply,Its great to hear from you in Shakespear land("BUEATIFULL COUNTRYSIDE") and many thanks for your comments.
I have printed all of the imfo and will deffinatly post a thread later on today.Have to just go and take some more medicane.......THX
Hi Ian
I have somewhere an old SA7 but can't really give any values as i'm currently in Bali. Do yourself a favour and disconnect the balance pot. Firther improvements can be had if you replace the 12AY7 with something with lower Rp and get rid of the follower. 6N1P? I fully agree with Frank that putting too much effort into it is not really worthwhile.
cheers
peter
I have somewhere an old SA7 but can't really give any values as i'm currently in Bali. Do yourself a favour and disconnect the balance pot. Firther improvements can be had if you replace the 12AY7 with something with lower Rp and get rid of the follower. 6N1P? I fully agree with Frank that putting too much effort into it is not really worthwhile.
cheers
peter
12AY7?
Hi Peter,
To the best of my knowledge the SA-7 never had any of those in it,did you mean 6DJ8 perhaps?
Also keep in mind the 6N1-P requires more heater current than the 6DJ8.
I would recommend the Sovtek 6922 AKA 6N23-EB if the valves require replacement.
Cheers,
P.S. Enjoy your trip.
Hi Peter,
To the best of my knowledge the SA-7 never had any of those in it,did you mean 6DJ8 perhaps?
Also keep in mind the 6N1-P requires more heater current than the 6DJ8.
I would recommend the Sovtek 6922 AKA 6N23-EB if the valves require replacement.
Cheers,
P.S. Enjoy your trip.
Hi Ian,
Sorry to hear of your current misfortune and hope you are soon better.
It never ceases to amaze me that one can feel so really rotten with a simple cold, and yet although we can put a man on the moon, we don't have any effective remedies for this, nor any good preventatives.
You are absolutely right about how lucky I am living here out in the country. I am looking out of the window now with the sun beaming down on the open fields around us, and approx. 40 semi-tame pheasants have just been in our back garden to have their usual breakfast!
It cannot get any better.
Regards,
Sorry to hear of your current misfortune and hope you are soon better.
It never ceases to amaze me that one can feel so really rotten with a simple cold, and yet although we can put a man on the moon, we don't have any effective remedies for this, nor any good preventatives.
You are absolutely right about how lucky I am living here out in the country. I am looking out of the window now with the sun beaming down on the open fields around us, and approx. 40 semi-tame pheasants have just been in our back garden to have their usual breakfast!
It cannot get any better.
Regards,
Hi Bob,Frank and Peter,Great imfo.
Hi Bob,
Thankyou for the exellent imfo.
I think that the sa-7 does indeed use a 12axy Bob.According to the alta vista website models made in 1984 used this valve and later ones used the 6922.I was deffinately looking at some new valves Bob as the unit i bought does not have any in it and is currently sitting redundant on the hi-fi rack.
Hows the seen in Africa with hi-fi bob?Great to hear from you.
Thankyou,
Ian.
Hi Bob,
Thankyou for the exellent imfo.
I think that the sa-7 does indeed use a 12axy Bob.According to the alta vista website models made in 1984 used this valve and later ones used the 6922.I was deffinately looking at some new valves Bob as the unit i bought does not have any in it and is currently sitting redundant on the hi-fi rack.
Hows the seen in Africa with hi-fi bob?Great to hear from you.
Thankyou,
Ian.
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