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    Dynaco Pass 3X preamp

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    kevinmi

    Posts: 53
    Join date: 2009-11-17

    Dynaco Pass 3X preamp

    Post by kevinmi on Fri Dec 04, 2009 4:19 am

    I just bought a Pass 3X pre in original, no mods, good shape condition. Should I spend the time and money to upgrade this unit with the new boards that are available, or should I just use it as is until it quits working? I haven't even plugged it in yet, so I don't know how it sounds. I guess I'm wondering if it's worth more to keep it original or modifiying it? Also, is there a market for these preamps? I've got $260.00 wrapped up in this unit, and I'd be willing to sell it for the same price to someone who is looking for an unmolested pass 3X before I butcher it up.

    Bob Latino
    Admin

    Posts: 1910
    Join date: 2008-11-27
    Location: Massachusetts

    Re: Dynaco Pass 3X preamp

    Post by Bob Latino on Fri Dec 04, 2009 5:33 am

    kevinmi wrote:I just bought a Pass 3X pre in original, no mods, good shape condition. Should I spend the time and money to upgrade this unit with the new boards that are available, or should I just use it as is until it quits working? I haven't even plugged it in yet, so I don't know how it sounds. I guess I'm wondering if it's worth more to keep it original or modifiying it? Also, is there a market for these preamps? I've got $260.00 wrapped up in this unit, and I'd be willing to sell it for the same price to someone who is looking for an unmolested pass 3X before I butcher it up.

    Hi Kevin,

    The Dynaco PAS preamps need to be heavily modified in order to really give accurate sound by today's standards. If you do modify your preamp you usually can never recover the funds needed to do the modifications should you ever decide to sell the preamp. A PAS preamp is nearly always worth more in stock "unmolested" condition. Any future prospective buyer for your preamp will be suspicious of exactly what mods were done to the preamp and not willing to "pay extra" for the mods.

    If you want the best sound out of your amp my advice would be to just sell the preamp outright as it is right now in its unmolested form and use the money recovered to get another preamp. If you are into kits then the Tubes4hifi SP-8 preamp KIT gives top notch sound quality for $700 - $800 or so. Another option is to buy an older used tube preamp on Audiogon from USA companies like Conrad Johnson, Audio Research, BAT, Joule Electra or Rogue. Some of their older units from the 1980's and 1990's can be had for 40 to 50% of their original price. They are well made and these companies still support their older preamps in case the unit should ever need service in the future.

    Bob


    Last edited by Bob Latino on Mon Dec 14, 2009 4:16 am; edited 1 time in total

    kevinmi

    Posts: 53
    Join date: 2009-11-17

    Re: Dynaco Pass 3X preamp

    Post by kevinmi on Fri Dec 04, 2009 1:54 pm

    Thanks for the advice, Bob. That is pretty much exactly what I was thinking also. I'll probably play around with this preamp for a bit and then sell it.

    tubes4hifi
    Admin

    Posts: 976
    Join date: 2008-11-30

    Re: Dynaco Pass 3X preamp

    Post by tubes4hifi on Sat Dec 05, 2009 2:11 am

    just in case no one else noticed, all of those preamps are line stage only except the BAT VK-3 which already sold, and they're all over $700, basic and simple but well built. The VTA SP8 preamp is a bargain with both phono and line stages, and can be built for $500-800 depending on the options and how much of the chassis work you want to do yourself.
    I agree with Bob, a PAS3 is worth more unmodified, but I have had customers spend up to $900 on upgrades over the $200+ they originally paid. My Zmod upgrade is the same circuit as my SP8 preamp which Bob gave a great review of, and the new SP9 circuit is available as an upgrade to the PAS3 which includes a premium quality tone control circuit.
    www.tubes4hifi.com/pre11.htm
    tubes4hifi preamp page


    Last edited by tubes4hifi on Sun Mar 13, 2011 4:42 am; edited 1 time in total

    kevinmi

    Posts: 53
    Join date: 2009-11-17

    Re: Dynaco Pass 3X preamp

    Post by kevinmi on Sat Dec 05, 2009 5:29 am

    I hooked up the Pas 3X pre last night, and to my suprise it sounds pretty good. I think I like the phono stage better than the one in my Mc C-39! This unit has been in storage for 30 years and looks brand new inside. I will not be modifying this unit, instead I'll just resell it. I'm anxious to try a newer tube preamp now!

    kevinmi

    Posts: 53
    Join date: 2009-11-17

    Re: Dynaco Pass 3X preamp

    Post by kevinmi on Wed Dec 09, 2009 4:13 am

    I did sell the Pass 3X preamp today. I'm going to miss the little guy! I haven't found a replacement yet, but it will definately be a tube pre with a tube phono stage!
    I like the idea of building a VTA pre kit, but I really want a remote control volume at least, and preferably input select also. I'm afraid that I would have too much money involved in a kit with all the options I want.

    Clik2media

    Posts: 40
    Join date: 2009-01-19

    Re: Dynaco Pass 3X preamp

    Post by Clik2media on Sun Dec 27, 2009 12:30 am

    Bob, when you say "PAS preamps need to be heavily modified in order to really give accurate sound by today's standards", Does that exclude new boards and modern electrolytics and perhaps rectifier, as too much modding for personeal use. [not reselling] Typically I only use them for FM reception on my FM3, I have a couple I want to experiment with, meaning differnt set up with differnt amp set-ups etc.

    Clik2media

    Posts: 40
    Join date: 2009-01-19

    Re: Dynaco Pass 3X preamp

    Post by Clik2media on Sun Dec 27, 2009 12:31 am

    Anyone have a layout for selenium rectifier for the PAS. thnx

    Bob Latino
    Admin

    Posts: 1910
    Join date: 2008-11-27
    Location: Massachusetts

    Re: Dynaco Pass 3X preamp

    Post by Bob Latino on Sun Dec 27, 2009 7:26 am

    Clik2media wrote:Bob, when you say "PAS preamps need to be heavily modified in order to really give accurate sound by today's standards", Does that exclude new boards and modern electrolytics and perhaps rectifier, as too much modding for personeal use. [not reselling] Typically I only use them for FM reception on my FM3, I have a couple I want to experiment with, meaning differnt set up with differnt amp set-ups etc.

    Hi,

    It is not new boards that the PAS preamps need but (IMHO) a new circuit. Just replacing the two original boards will help a little but you won't change the general character of this preamp by just replacing the boards.

    (IMHO again ..) The Dynaco tube AMPS were a lot better designed than the PAS PREAMPS and the PAS preamps really need heavy modification to sound as good as even a mildly modified Dynaco amp. The stock PAS-2 and PAS-3 preamps sound smooth, mellow but don't seem to have as much dynamic range as a modern preamp. There is less "jump" to the sound on orchestral peaks. The only PAS preamp that I ever heard that sounded very good was the PAS-4 which was built in the 1990's by Panor when they took over Dynaco. This PAS has a completely different circuit than the original PAS preamps. Unfortunately not too many of these were made and when you do see one up for bid on Ebay they usually sell for $500-$600.

    If you do want to experiment on one of your PAS preamps then there is information on the internet that deals with removal of the tone controls, beefing up the power supply and possibly some other mods that you can do on a stock PAS-2 or PAS-3 preamp. Understand though that you will probably devalue the preamp somewhat by modifying it. This would be something to consider should you decide to sell your PAS preamp at a later date.

    Bob

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