Hi, I have one PAS2 that sounds really great with the old caps and another that sounds just good but a little more dull and also has the old caps..,tubes are swapped with new and same, lacks hi end compared to the other one with original caps and bass pots seem to work at different levels ie one most action is at very end of sweep and the other in the middle. What tone Caps specifally should I focus on as opposed to just replacing all of them? I just did the filament caps. I read on one post someone suggested replacing all of the old caps but that seems a bit drastic. I don't really want to bypass the tone circuit which I hav e seen a lot of people suggest as I like having some control. Most of my DC voltages are ballpark so I was just going to focus on the tone caps first. I need a bit of help pointing out which ones they are. I am using phono primarily. I wonder if there was a doc that pointed out just the tone caps on a PAS 2 Specifically. THX for your time.
2 posters
PAS 2 Tone Caps Question
bubbasweet- Posts : 95
Join date : 2016-03-14
- Post n°2
Re: PAS 2 Tone Caps Question
UPDATE: Wow I decided to put my TV in the Aux input and sounds great. Then I tried my Phono via the Special input which I read was like a 2nd phono input and WOW amazing. So what is different about the phono input that could have given me such a good but non vibrant sound lacking the high end and mids that the Special input has? Are there extra caps on the phono input as opposed to the Special? I am so glad I tried that. THe amp sound great. I do have to lean the balance to one side a bit why is that? Seems one side is always louder on PAS amps balance wise? THX
peterh- Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden
- Post n°3
Re: PAS 2 Tone Caps Question
Have you tightened the knobs according to the manual ? This procedure is different forbubbasweet wrote:UPDATE: Wow I decided to put my TV in the Aux input and sounds great. Then I tried my Phono via the Special input which I read was like a 2nd phono input and WOW amazing. So what is different about the phono input that could have given me such a good but non vibrant sound lacking the high end and mids that the Special input has? Are there extra caps on the phono input as opposed to the Special? I am so glad I tried that. THe amp sound great. I do have to lean the balance to one side a bit why is that? Seems one side is always louder on PAS amps balance wise? THX
the X models.
The special input lacks riaa compensation ( unless the pas is modified)
Is you rpercieved difference only with phono input or is the line inputs also affected ?
bubbasweet- Posts : 95
Join date : 2016-03-14
- Post n°4
Re: PAS 2 Tone Caps Question
Just the photo input seems not as clear and well rounded. Am I imagining it or are there different components in it? I will go look at schem now just got busy. As well figured someone on here would have more experience with the Phono and Special than me. Until just recently I did not realize it was a dual phono input. I guess i should read.. A.D.D...
peterh- Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden
- Post n°5
Re: PAS 2 Tone Caps Question
If it is only the phono input that seems dull, then concentrate on that.bubbasweet wrote:Just the photo input seems not as clear and well rounded. Am I imagining it or are there different components in it? I will go look at schem now just got busy. As well figured someone on here would have more experience with the Phono and Special than me. Until just recently I did not realize it was a dual phono input. I guess i should read.. A.D.D...
It contains a number of high value resistors that might have drifted a lot.
If you don't feel confident with measuring them you can get a replacement board
fairly cheap that has all caps and resistors mounted. Just move over all connections
and tubes.
See this from vintage electron :
https://www.ebay.com/itm/NEW-STUFFED-BOARD-Dynaco-PAS-Preamp-PC-6A-Phono-PC-6-12AX7-USA/373274488675?hash=item56e8e4af63:g:knYAAOSwRrVfh4yG
bubbasweet- Posts : 95
Join date : 2016-03-14
- Post n°6
Re: PAS 2 Tone Caps Question
This might be a dunm question as I have rea many schematic but how do you read that SSC switch. WHen I look at it I have never been able to follow it. Like for example where doe the phono input land on the other side of where it hits the switch. I actually much like the Special input better than the photo input. On my Pames I used to use the 78 input but I now realize it has a special too. I just tried it and I just love it.
peterh- Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden
- Post n°7
Re: PAS 2 Tone Caps Question
The switch in the manual is shown in it's leftmost position.bubbasweet wrote:This might be a dunm question as I have rea many schematic but how do you read that SSC switch. WHen I look at it I have never been able to follow it. Like for example where doe the phono input land on the other side of where it hits the switch. I actually much like the Special input better than the photo input. On my Pames I used to use the 78 input but I now realize it has a special too. I just tried it and I just love it.
You have to turn it 2 clicks to get into phono position.
The special input is wired ( as default) for 78 rpm records. The manual
contains info howto convert to a second phono input. But that is not what you ask for, instead you feel that the special fits your phone better. That could be an indication
that some components has drifted and needs replacing.
If you want to figiure out then start with comparing the amp with the dynaco manual and see if it is modified in any way.
Next step would be to examine components one by one ( or replace the board )
All you need is a screwdriver a plier and a soldering gun.
bubbasweet- Posts : 95
Join date : 2016-03-14
- Post n°8
Re: PAS 2 Tone Caps Question
I can's see where it leaves the switch. That is my problem. Yes just did the Filament Caps on all 3 of my preamps and a buddys. This Special input does it for me. So I am leaving it. I no longer just max my treble. I have room to play now.