The Dynaco Tube Audio Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.
The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all Dynakitparts.com products


    Need opinions on new equipment acquired

    gjmess
    gjmess

    Posts : 9
    Join date : 2020-10-16

    Need opinions on new equipment acquired Empty Need opinions on new equipment acquired

    Post by gjmess on Mon Oct 19, 2020 12:45 pm

    Hello all,
    Need opinions on what to do with the newly acquired Dynaco equipment I purchased recently.  I found a ST-70, Pas 3X, a tuner, speakers and a turntable.  It was playing in the store when I bought it.  Anyway...looked at the bias and adjusted and have been playing it.  Everything is original.  Which is my dilemma...would like to keep it as original as possible but everything I read talks about tweaks and mods that enhance these thing immensely.  I know I would like to change the output terminals and the input jacks on the amp.  Easy and can always convert back...if needed.  Power supplies seem to be a easy decision...just the extent.  Any suggestions would be greatly appreciated.   See if I can attach a pic or two...Need opinions on new equipment acquired 20201012 Need opinions on new equipment acquired 20201013
    peterh
    peterh

    Posts : 1456
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by peterh on Mon Oct 19, 2020 1:05 pm

    Congratulations
    It's gettin rare to find unmolested dynaco stuff.
    The power tubes in st70 is consumables, make sure you get matched pair or a matched quad.
    The weakest point is imho the bias rectifier in the st70. Get a kit with instructions from
    dynakitparts.com :
    https://www.dynakitparts.com/shop/st-70-bias-circuit-kit/

    gjmess
    gjmess

    Posts : 9
    Join date : 2020-10-16

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by gjmess on Mon Oct 19, 2020 1:24 pm

    Thanks for the input. I will be getting one of those and probably some output jacks and input jacks from there.
    WLT
    WLT

    Posts : 127
    Join date : 2013-07-13
    Location : Rochester NY

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by WLT on Mon Oct 19, 2020 2:26 pm

    Clean and well worth keeping as original as possible. The input and output terminals are not that bad either. Probably need a good cleaning though. The issue is getting the right interconnect cables/wires to work well with the original terminals. If you can make your own cable/wires I can send info on what I think works well.

    Having said that most on this forum would recommend replacing the capacitors. Particularly the power supply and bias supply caps. They are available to look and work the same as the originals. Try those first and see if that is good enough for your audio needs. Replacing the out of spec resistors is of value as well. You can still find the carbon composition type if you want them although many will recommend other more modern types. Going down the rabbit hole at that point.

    WLT
    WLT

    Posts : 127
    Join date : 2013-07-13
    Location : Rochester NY

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by WLT on Mon Oct 19, 2020 2:28 pm

    BTW - I had a pair of IMF TLS80 and your avatar looks just like them.
    gjmess
    gjmess

    Posts : 9
    Join date : 2020-10-16

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by gjmess on Mon Oct 19, 2020 2:39 pm

    Thanks for the info....yep...TLS 80....love them. I'll take a look at the input and output jacks. I have a cheap pair of cables from some vcr or something that I am using now. They barely fit. Also thinking about swapping the mono/stereo with the power switch so it's in front....easy to switch back.
    WLT
    WLT

    Posts : 127
    Join date : 2013-07-13
    Location : Rochester NY

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by WLT on Mon Oct 19, 2020 3:13 pm

    Give some thought to the power switch change. You will be running 120 VAC thru the amp instead of keeping it in the back near the transformer. I have fixed many Dynacos with hum problems due to poor planning and improper wiring routing. It is not hard to reach over the amp to turn on and off. My grandson does it for me all the time.

    Try the following for speaker connections - 10 ga wire and connectors that fit the Dyanco terminals properly. Just have to crimp and solder. Other end can be these or banana type. Different lengths available.

    https://www.ebay.com/itm/20-PACK-10-GAUGE-100-COPPER-GOLD-SPADE-TERMINALS-10-RED-10-BLACK-BOOTS-8/263323881483?hash=item3d4f53900b:g:PtAAAOSw1BtZd8f6

    https://www.ebay.com/itm/KnuKonceptz-Kord-Speaker-Wire-Ultra-Flex-Blue-OFC-10-Gauge-Cable-25-True-AWG-/390593267272?hash=item5af12c4648
    avatar
    rjpjnk

    Posts : 264
    Join date : 2018-07-18

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by rjpjnk on Mon Oct 19, 2020 7:21 pm

    Lucky Duck! I'll give you 50 bucks for those junky old Great Britan OEM Dynaco power tubes Wink

    Just kidding, they're worth a lot more than that. You have quite a find there.

    Shame to touch it at all. Tough one.
    WLT
    WLT

    Posts : 127
    Join date : 2013-07-13
    Location : Rochester NY

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by WLT on Mon Oct 19, 2020 8:52 pm

    If you find the cables to the speakers easy to make up then you may want to try the RCA interconnects. This cable is very good and the connectors fit so they do not touch each other when in the stock ST70 input jacks. Solder connections only

    RCA cables – Use either Belden 8412 or Mogami W2549 microphone cables. These are two wires with an outer shield. The toughest part is grounding one end of the shield after connecting both the inner conductors. The connectors are Switchcraft 3502. Several finishes available. I have used mostly the AAU and like them a lot. I do not sell or work for any of these manufacturers but I do like all the products I listed.

    My opinion - With these cables/wires in and out there is really no need to change the terminals on the amp in any way.
    gjmess
    gjmess

    Posts : 9
    Join date : 2020-10-16

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by gjmess on Tue Oct 20, 2020 8:39 am

    Thanks for all the info and parts list. Will definitely try your recommendations.
    billinrio
    billinrio

    Posts : 104
    Join date : 2018-01-03

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by billinrio on Tue Oct 20, 2020 9:26 am

    I'm very surprised that nobody has yet mentioned the power supply of the PAS 3x, with its selenium rectifier, as a likely candidate for replacement. Also, due to possible heat issues, about perhaps not stacking the tuner on top of the preamp.
    peterh
    peterh

    Posts : 1456
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by peterh on Tue Oct 20, 2020 10:14 am

    billinrio wrote:I'm very surprised that nobody has yet mentioned the power supply of the PAS 3x, with its selenium rectifier, as a likely candidate for replacement. Also, due to heat issues, about perhaps not stacking the tuner on top of the preamp.

    The PAS will heat as little as the tuner ( 16w ) , none of them gets warm

    As for the power supply in the pas , Z-PSU
    ( http://www.erhard-audio.com/Power_Supply_Kits.html )
    will replace all cancap se -rectifier and electrolytics in the flament circuit) for $45.

    Sponsored content

    Need opinions on new equipment acquired Empty Re: Need opinions on new equipment acquired

    Post by Sponsored content


      Current date/time is Sat Dec 05, 2020 4:32 am