what values did you use for C5,22,27,28?
c5 asks for .056mfd but all they have is .047 or .068
c22 asks for .027mfd but all they have is the .022mfd orange drop
c27 asks for .0082mfd but all they have is the .0068mfd mustard
c28 asks for .02mfd but all they have is the orange drop .022mfd
im starting to see double. im going to have to go over the list again tomorrow i think
thanks
c5 asks for .056mfd but all they have is .047 or .068
c22 asks for .027mfd but all they have is the .022mfd orange drop
c27 asks for .0082mfd but all they have is the .0068mfd mustard
c28 asks for .02mfd but all they have is the orange drop .022mfd
im starting to see double. im going to have to go over the list again tomorrow i think
thanks
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I use for C5 Sozo .068 uF
I use for C22 Sozo .022 uF
I use for C27 Sozo .0068 uF
I still have not changed C28 ..............
RMC N.O.S. .02 500v vintage tone caps for lps-Fenders - eBay (item 380212685174 end time Apr-04-10 17:34:40 PDT)
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rewiring switches
did you have any trouble rewiring the switches? i cant figure out how the lugs are numbered. it says the c28 ac ceramic disc cap goes between lugs 2 and 3 on the power switch, so i look on the schematic and i see it there so i assume those lugs are 2 and 3. then when i continue to wire the B and AS switches with those short jumpers the logic seems to break down. what it says in the instructions does not reflect what it shows on the schematic.
did you rewire these?
thanks
did you have any trouble rewiring the switches? i cant figure out how the lugs are numbered. it says the c28 ac ceramic disc cap goes between lugs 2 and 3 on the power switch, so i look on the schematic and i see it there so i assume those lugs are 2 and 3. then when i continue to wire the B and AS switches with those short jumpers the logic seems to break down. what it says in the instructions does not reflect what it shows on the schematic.
did you rewire these?
thanks
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Yes I did , take the care, ...................I recommend that you take pictures first ,so you don't make any mistake..
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i allready took it apart thinking i could rely on the instructions. the power switch used to glow when it was in the off position.
do you recall how they are numbered? top right is 1 bottom left is 6?
thanks
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I'm doing something familiar with an old Dynaco PAT-4. I am replacing all of the signal capacitors and upgrading the power supply too.
In my case, the tone controls will be bypassed (as mentioned on the AVA site), which also allows C21 to be replaced with a length of wire. I'm also thinking of completely replacing the power supply as the stock CRCRC isn't the greatest thing out there. A little toroid and an LM317 board might be better or perhaps an offboard switching supply with some internal capacitors to reduce any hash.
I've done a major rebuild on a Dynaco SCA-80Q and found that the new capacitors really modernized the sound. I was shocked at the difference some new (and modern) components made to this easily dismissed integrated.
In my case, the tone controls will be bypassed (as mentioned on the AVA site), which also allows C21 to be replaced with a length of wire. I'm also thinking of completely replacing the power supply as the stock CRCRC isn't the greatest thing out there. A little toroid and an LM317 board might be better or perhaps an offboard switching supply with some internal capacitors to reduce any hash.
I've done a major rebuild on a Dynaco SCA-80Q and found that the new capacitors really modernized the sound. I was shocked at the difference some new (and modern) components made to this easily dismissed integrated.
i wonder how much of this is a waste of components since nobody seem to bother to see crosstalk figures and how better this machine could play if rewired
to my opinion this style of wiring is more or less tube style that now days sobody will do Having line, phono, and power cables all messed up its probably something not good for a pre ...
I would rearrange all wiring before doing anything else ....use coax if possible everywhere , see for ground issues and try to keep power cables away if possible ...
i like my equipment symmetrial clean and organized but that is just a personal opinion
creetings sakis
to my opinion this style of wiring is more or less tube style that now days sobody will do Having line, phono, and power cables all messed up its probably something not good for a pre ...
I would rearrange all wiring before doing anything else ....use coax if possible everywhere , see for ground issues and try to keep power cables away if possible ...
i like my equipment symmetrial clean and organized but that is just a personal opinion
creetings sakis
this is more of a 'lets burn some hours away while my wife studies' project. I'm just getting my feet wet with solid state, having spent the previous 20 years building and modifying tube gear.
I certainly don't expect world class performance for a free unit + $30 worth of new parts! But I am hoping for something 'good enough' to be used in my all vintage second stereo system as my refurbished PAS-3X needs a full rebuild with new switches and pots.
I certainly don't expect world class performance for a free unit + $30 worth of new parts! But I am hoping for something 'good enough' to be used in my all vintage second stereo system as my refurbished PAS-3X needs a full rebuild with new switches and pots.
stock, the Dynaco PAT-4 is indeed a nasty little preamplifier - I checked it out yesterday on my decidedly less-than-hi-fi vintage system (McIntosh 250 amplifier, KEF Q60 speakers and Pioneer DVD player). Compared to the venerable PAS-3, the PAT-4 was rather harsh sounding with the classic early 'transistor' sound. The Threshold preamp(s) in my main system runs rings around this thing.
I'll be curious to see how some film caps (instead of electrolytic couplers), a tone control bypass and power supply cap replacement effects the measurements and sound. At this stage, it certainly couldn't hurt. My loss is only a few hours of time and a few dollars. If I don't like the results, I'll pull the guts and build something else inside.
I'll be curious to see how some film caps (instead of electrolytic couplers), a tone control bypass and power supply cap replacement effects the measurements and sound. At this stage, it certainly couldn't hurt. My loss is only a few hours of time and a few dollars. If I don't like the results, I'll pull the guts and build something else inside.
I LOVE DETAILED PRESENTATIONS .... i wonder though why there is no crosstalk measured ...
also propbably nobody can tell anything if one more working source is conected to the preamp .... of course i am no perfectionist and my argument is based on : if some one spents time and money to fill this box with so many goodies may as well to the rest of the things which is the proper wiring and may be some relay shunt selector ....
I've seen done before - using the PAT case work to build a Super PAS.
Last night, I finished up replacing the various leaky electrolytics and bypassing the tone controls. A quick listen on both my systems revealed an improved preamplifier - certainly not world class, but much better than I expected. The power supply is still stock as I wanted to test out the boards before I did any more work.
hello.
the last weeks i have built a copy of the dynaco pat4 preamp.the picture shows the old school-version,with carbon res,bc109 transistors (but this foto shows bc549 in the phono part), big electrolytics in the signal path..........
in the psu i used bigger elcaps (2200uF),the transformer has 2x18Vac in series,5W.
tone controls and loudness-function are left out.
at the moment it is a wire nest,but when built into the case it will look fine i think.
the last weeks i have built a copy of the dynaco pat4 preamp.the picture shows the old school-version,with carbon res,bc109 transistors (but this foto shows bc549 in the phono part), big electrolytics in the signal path..........
in the psu i used bigger elcaps (2200uF),the transformer has 2x18Vac in series,5W.
tone controls and loudness-function are left out.
at the moment it is a wire nest,but when built into the case it will look fine i think.
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