Vintage stereo McIntosh MC30s - MX110z Project - Progression of Setup (An Issue, Can you Help?)

Discussion in 'Audio Hardware' started by zenarrow, May 14, 2018.

  1. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    A few months back I started thinking about my system and where I stood. So let's start at the begining. I got a great deal on a JA Michell Gyro SE Turntable a number of years back, Had a pair of Altec Lansing 890 Boleros. Wanted to dive into tubes loved the idea of them and the aesthetics of them as well. So I started with the basics a Dynaco ST-70 with a Pas 2. Sounded wonderful. I did the basic upgrades to the PS and changed out some caps on the Pas 2, kept it mostly orig with the tone controls and everything. Never an issue, always sounding fantastic. Then I came across a garage sale a few springs ago where I found a pair of Altec Lansing Model 14's. Got a super deal on those too. Had to have them re-foamed via Great Plains Audio. Well worth it.
    Again sounded great, I have been told though that the ST-70 and the Pas 2 were the weak link in my system, so finally I decided to make a move.

    Started reading and desiring a vintage McIntosh set-up. After doing research I decided that a pair of MC30's suited me best. So i found a pair and bought them like a month or so ago. Seller had done PS and changed out some bad caps. So they arrived in good order.
    When they arrived :
    [​IMG]P1010005 by Joe Hancock, on Flickr

    A little pitting on them but that was ok. With only the Pas 2 I hooked them up to test them out. Right away I as well as my wife was floored at the sound. So much depth and warmth to them. My wife pointed out though, that the upper end seemed a little shrill, especially the vocals being extremly "Bright" Like the top end was almost falling apart. (I noticed too but didn't want to admit it to her, or myself to be honest)
    I chalked it up to the Pas 2 not being up to par with the 30's.
    Here is the system at that stage:
    [​IMG]P1010001 by Joe Hancock, on Flickr

    I then spent a long time (kinda) researching the proper preamp. My first temptation was the c20, had recommendations for this from my old audio master who got me introduced into tube audio, who sold me the Gyro SE. Then punching into the google machine the proper preamp for the 30's I kept getting directed here to the Steve Hoffman forums, one of my favorite haunts already. I suppose you can guess where this is leading, yep you are right I fell in love with the MX110z. I found the right one as it seemed to present itself to me on eBay listing ending with just a few hours left. Offers accepted, for a reasonable shipping price, but, in the listing it said local pick up only. So I messaged the seller and asked about the conflict, he stated that he had no idea it had said local pick up only, and promptly removed it. Talked to him a little about the amp, it was his fathers, one owner only. I will post more detailed photo's of the unit soon. Time running out I made a fair offer-accepted the rest is history. All original tubes and orig case and no upgrades done, a true artifact. I found the most beautiful specimen of such, and a beauty too;
    [​IMG]Screen Shot 2018-05-07 at 8.20.23 AM by Joe Hancock, on Flickr

    I am positive that detail kept the MX110z from being sold , before I made an offer on it.

    Here is a picture of the system sans the Pas 2 With the MC30's and MX110z:
    [​IMG]P1010005 by Joe Hancock, on Flickr
    I did soon after ditch the vintage fans off the space.

    So I was on days off with time to listen- listen- listen. Had some friends over and we listened to all kinds of music, Monks Dream, Wilco, White Stripes, Pink Floyd Meddle, Sade Diamond Life etc etc.

    After they left, me and my wife discussed the experience. Again, the system seemed bright and the top end seemed to be cut off once more.
    So I went to adjusting things, tuned the gains on the 30's maxed out, used little of the volume on the pre. Turned the gains all the way down, had the volume set to 2 o'clock. Had the loudness switch on, then off, with the HF filters on/off and the LF on/off. Adjusted the treble and bass to different settings. I was defeated, spirit broken, I thought the MX110z was a bust, wondered where and how much it would be to have it shipped off somewhere to be gone through.
    Then I remembered the MC30's with the Pas 2 and the same issue, didn't dawn on me until yesterday. So I replaced the MC30's with the Dynaco ST-70, and wouldn't you know it, issue is gone.... My MX110z is a true champion all original thoroughbred.
    At times this, when I play Jazz records it is stunning and magically musical.

    That leaves me though with the issue of the 30's. I followed many peoples advice here on this forum about tube rolling and position with the 30's and here is my set-up as it now stands.
    I have some very nice vintage (tested great) telefunken 12ax7's in first and last slots. Mullard 12AU7's in the second slot (these tested great too).
    The pair of 12bh7's that came with the 30's. The 5UA an RCA and a Slyvania, that came with them as well. Also, the output tubes are 6L6's reproduction TAD's. I tried using some branded Seeburg Rca Black plated 6L6's. No difference, also swithcing out the 12bh7's from another pair of Seeburg mono blocks, no difference.
    So now I have the MX110z with the ST-70 and it does sound freakin' amazing. But I want my 30's to be with my preamp, but the shrillness is just too fatiguing.
    Does anyone have any advice or tips that I may try to loss this problem? All responses will be greatly appreciated. I am desperate. I have had people tell me it is this way because I am hearing the truest form of the music that I can finally hear the poor quality of certain recordings, I do not believe that to be true. I have tried isolating each amp and both seem to have the exact issue. I am so sad, because it sounds so nice with the ST-70, I can only imagine what it will sound with these 30's.
    Here is a picture of my system as it stands now.
    [​IMG]20180513_222525 by Joe Hancock, on Flickr
     
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  2. beowulf

    beowulf Forum Resident

    Location:
    Chula Vista, CA
    Wow, congrats on a very cool vintage system! This would actually be my dream setup for a second system. I would think it's possible that you have some bad caps or resistors. If you're super handy with a soldering iron and circuit schematics you could possibly do the work yourself, but I'm not and the first thing I would do is take it to a competent technician who knows how to work on vintage amplifiers, etc. and have him go completely through it.
     
    zenarrow likes this.
  3. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    A pricier route would be to send them to Vintage Vacuum Audio for a complete renovation, which I think costs around $700. I do know they restore both the cosmetics as well as the electronics of the amps.
     
  4. beavis

    beavis Forum Resident

    Location:
    Sayre, Pa. USA
    I had the exact same set-up ten years ago.....MX110Z and a pair of MC30s.....had all of them refreshed by Terry DeWick and never heard a 'shrillness' to them at all....at their age they can all use a trip to the doctor.
    Now many will laugh at this (and I'll get flamed) but.....turn the plugs around in your power strip; the polarity may be off...one component at a time....and see if that makes things 'better'.
     
  5. KT88

    KT88 Forum Resident

    Easy adjustment:

    Lower HF level on loudspeakers
    Lower MF level on loudspeakers

    Easy component swaps:

    12AX7 Tubes in power amp
    12AU7 Tubes in power amp

    If none of that works well enough for you, then look into the front end:

    12AX7 Tubes in phono section of preamp
    Phono cartridge

    Last recourses:

    Modify loudspeaker horn directivity and output by placing some heavy cloth or thin felt behind grilles in front of horns. Try either tweeter of midgrange depending upon what you find when adjusting those levels controls.
    Recap loudspeaker crossovers
    Inspect amplifier restoration repairs and see what quality of work was done, soldering and component choices.

    -Bill
     
  6. IanL

    IanL Forum Resident

    Location:
    Oneonta, NY USA
    I agree that you should have the amps gone over by a qualified technician. After that, get some NOS GE 6L6GC's in there. Your other tubes all sound great. You are VERY close to having a killer-sounding system!
     
    zenarrow likes this.
  7. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    Here is what was listed on the page when I bought them:
    "McIntosh MC30 pair,in good working condition,both amps are fully restored,new CE main electrolytic capacitors,new power cords and thermistors added for power supply protection,all coupling capacitors are original capacitors except we found six caps in leaking condition was replaced NOS Sprague Black Beauty caps,some out of spec resistors replaced,MC30 with serial#5E306 and serial#7E946,both amps have rust spot chrome chassis,all lettering intact but do have some age spots,the transformers are all good but do have some rust spots (See Photo's)not perfect but good,both amps have Telfunken 12AX7's ,US version tubes and TAD 6L6GC's all other tubes are US versions,We strive to retain the original sound of these classic gems,All restoration work preformed by the audio experts at Audio Exchange Atlanta,Ga"

    Has anyone ever dealt with this fellow at Audio Exchange? It is who I actually bought the amps from, I have tried contacting him with no response as of yet.

    I have all these already, the pre has the Tele's 12AX7's in the phono.
    The 30's have the 12AX7's - Teles -first and last slot and the 12au7 in the 2nd slot - Mullard

    I think this will be my next step.
     
  8. IanL

    IanL Forum Resident

    Location:
    Oneonta, NY USA
    Very nice tubes. Mullard 12AU7s are wonderful! I use them in my DAC (most of the time). And Telfunken 12AX7s, not always my favorite 12AX7, but in these vintage McIntosh pieces, absolutely! Especially the phono section of the MX110. I owned an MX110z and an MC240 for about a decade, so I speak from experience.
     
    zenarrow likes this.
  9. rl1856

    rl1856 Forum Resident

    Location:
    SC
    The proprietor of Audio Exchange is a good guy and a qualified technician. Unless you commission a full rebuild, he only replaces what needs to be replaced, and likes to retain vintage character whenever possible. I dealt with him when I lived in Atl. His Ebay ID is "300B"

    I notice your ST70 has the original circuit caps. Even if everything tests well, stock 50+yr old parts will sound soft and mellow, or make other components sound bright in comparison....which is what you experience. You may be used to the sound of the ST70 as is. If the caps in the MC30s were changed just before you purchased the amps, it is very possible that the caps need to break in to sound at their best. See if you can leave the amps on and running continuously for a few days, then listen again. And experiment with tubes. RCA Black Plate 6L6GC pairs and quads are easily found, and prices at not too bad.

    I have owned rebuilt MC30s, and the amps were among the best amps I have heard. There is hope !
     
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  10. Chazz

    Chazz Music Addict

    Location:
    Southeastern, US
    Maybe a dumb question but, what is the power strip you are using? If it is one of those cheaper ones that is not designed for audio equipment, remove it from the system. They tend to kill the sound, especially with amps. Try plugging the MC30's straight into a wall outlet and see if the sound changes. They still may need to be checked out but give this a try first. I am very familiar with MC30's and they are wonderful sounding, not shrill by any means.
     
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  11. Mugrug12

    Mugrug12 Black book/Grappling hook

    Location:
    San Francisco
    When you say you isolated the amps, did you do so w he exact same tubes in in each one? Do you have any mono albums to test like this? Just thinking out loud...
     
  12. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    Sounds like a very good Idea, I may be used to the old softer ST-70, maybe I just need to let it burn in a while. Thanks.


    Nothing more than turning the gain all the way down and listening through each channel. But each side seemed to be "suffering" with the same "brightness" but no, nothing more than this simple test.

    A very cheap one in fact. I may just plug everything into the wall, good thinking.

    I have seen you around on every MC30 thread I have been reading, glad you are here for sure IanL

    Sounds like some good advice already. I will get these into action asap.
     
  13. KT88

    KT88 Forum Resident

    Try running the amps with the input attenuators at about their half way point. Have you tried adjusting the speakers? That seems to be most obvious to me. Horns can be very loud, and you have the ability to attenuate the top end this way, without doing anything to the amps.
    -Bill
     
  14. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Here is some useful information od the design of the Altec Lansing Model 19's.

    They feature the Manta Ray horn, which is designed to prevent direct beaming of higher frequencies, by the even dispersal of all frequencies that are handled by the Manta Ray horns.
     
  15. KT88

    KT88 Forum Resident

    They all claim that. The truth is that horn systems are as loud as God. I had a pair of 19's which I could crank in a basement, practically sealed without windows, and you could hear them across the street. :). I also had a pair of VOTT speakers, which I have no idea how painful they would be as I never even attempted anything other than little 5w - 12w tube amps through them. A better balance is to turn them down a bit IME.
    -Bill
     
  16. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    Jut another quick pic of the MX110z. Going to turn these on for a few days with speaker wires hooked up and let the tubes burn for a while.
    [​IMG]P1010009 by Joe Hancock, on Flickr
     
  17. Steve Hoffman

    Steve Hoffman Your Host Your Host

    Really no need to do that...
     
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  18. Guitarded

    Guitarded Forum Resident

    Location:
    Montana
    That 110Z is gorgeous. Nice grab

    I have also benefitted from the mistaken Local Sales Only sanfu.
     
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  19. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    I don't think it's a good idea to leave tube amps on for that long.
     
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  20. IanL

    IanL Forum Resident

    Location:
    Oneonta, NY USA
    I agree. Don't put the time on the tubes without listening/enjoying. If you aren't able to enjoy it, then get the amps checked out.

    And beautiful MX110!
     
  21. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    OK, now unplugged. Thanks, can't wait till Thursday Morning to do some more listening.

    Pretty strange, that it lasted for the 30 day listing, and no one else asked about it until the last hour when I finally contacted them.
    Yeah it is absolutely 10/10 cosmetically and sound wise with the ST-70, I am sure once I figure out the issues with the 30's my system will be the best in the western half of Lonely Wyoming
    Thank you guys very much, I truly love it, in it's wooden case too. Sorry if I am posting too many pics.... But it is so nice, the 30's are nice but the preamp is stunningly beautiful. I had no idea it would be so nice and have so much of my attention.

    [​IMG]P1010002 by Joe Hancock, on Flickr

    [​IMG]P1010007 by Joe Hancock, on Flickr
     
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  22. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    Does the MX110Z only have 1 AUX input?
     
  23. zenarrow

    zenarrow Well-Known Member Thread Starter

    Location:
    Wyoming
    Yes,
     
  24. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    Hmm, that would make it difficult to use with an outboard phonostage and CD player.
     
  25. Steve Hoffman

    Steve Hoffman Your Host Your Host

    The phono stage in the MX-110Z is magic. Why use an outboard phono? Defeats the purpose of having the thing..
     
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