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    Connecting a CD recorder to my SP/PH10

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    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Fri Oct 24, 2014 11:14 am

    Last year I bought my VTA ST-70 with the SP10/Ph10 preamp. I also bought a nice Music Hall turntable and about a zillion LPs to go with my already accumulated LPs. I'd like to be able to record some of these records to CD either for friends of just for listening in the car.

    I had originally hooked up a Zoom H1....

    http://www.zzounds.com/item--ZOMH1

    and it caused the vol. of the system to drop drastically. Troy figured out that the impedance mismatch was too much for this thing to work. Now I'm considering this one....

    http://www.amazon.com/dp/B00JYFAWMS/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2LBWBAA6MZR27&coliid=I2K3TAMJEP6HWS

    Do you think this will work okay with my rig?

    Thanks in advance.
    Dave





    colin86325

    Posts : 40
    Join date : 2014-04-01

    Re: Connecting a CD recorder to my SP/PH10

    Post by colin86325 on Fri Oct 24, 2014 4:41 pm

    No experience but that Zoom reminds me of an electric razor!

    turbotoy

    Posts : 47
    Join date : 2012-04-15

    Re: Connecting a CD recorder to my SP/PH10

    Post by turbotoy on Fri Oct 24, 2014 5:47 pm

    You really shouldn't connect any interconnects or other load (e.g. CD recorder) directly to the PH10, as the circuit lacks a buffer and relies on having a 100K output load from the volume attenuator of the preamp. The better thing to do would be to simply use the output of the SP10 with the volume adjusted to the proper level. The SP10 would effectively be acting as a buffer in this configuration. While that adds extra noise due to the gain of the SP10, in this application that is probably irrelavant and that's probably the best solution.

    Why not simply use a computer to burn the CDs? Decent sound cards are much cheaper than the recorder you are conisdering buying, and in reality the input on most motherboards would probably produce acceptable results.

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Fri Oct 24, 2014 6:45 pm

    Well, the SP10 has a tape out. What's it for? Is a CD recorder input that different from a cassette deck?
    I wasn't going to connect anything directly to the PH 10 as it is built into the SP10.
    The physical locations of the turntable and computer make direct recording impossible.

    bluerondo

    Posts : 27
    Join date : 2014-09-21
    Location : Irvine, CA

    Re: Connecting a CD recorder to my SP/PH10

    Post by bluerondo on Sat Oct 25, 2014 12:13 am

    The Zoom input impedance does appear to be a bit low. Input impedance: 2kΩ (Input level: 0 to -39dBm). Normal line level input impedance is usually 10k-20k. So not knowing what the output impedance is on the SP10?... but it it's much higher then the Zoom would attenuate the signal. I have recorded maybe over a hundred lps onto CD using my Mac G4 or newer Macbook with great results. I used Peak LE which is now out of business but there's Audaiity(free) now. It's nice to be able to see the waveforms and select track regions and avoid any large glitches between tracks. Peak was great because it was able to burn a Redbook CD direcly and if you did everything right importing into iTunes would automatically name all the tracks for you. Good luck.

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Sat Oct 25, 2014 9:42 am

    Here's the Tascam info from:

    http://tascam.com/product/cd-rw900mkii/specifications/

    Any reason this won't work with my system? Thanks.


    ANALOG IN
    Unbalanced
    Connector RCA pin jack
    Input impedance 22kΩ +/-10% (unbalanced)
    Reference input level -10dBV (Full scale -16dB)
    Minimum input level -19dBV (adjustable level at Full Scale -16dB)

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Connecting a CD recorder to my SP/PH10

    Post by peterh on Sat Oct 25, 2014 10:20 am

    Dave_in_Va wrote:Here's the Tascam info from:

    http://tascam.com/product/cd-rw900mkii/specifications/

    Any reason this won't work with my system? Thanks.


    ANALOG IN
    Unbalanced
    Connector RCA pin jack
    Input impedance 22kΩ +/-10% (unbalanced)
    Reference input level -10dBV (Full scale -16dB)
    Minimum input level -19dBV (adjustable level at Full Scale -16dB)
    The reason is that 22kohm is way too low for a tubeamp that lacks output buffers.
    Most tube preams are made for the loading of a tube powerstage, typically hundreds of kohms.
    You need a buffer between the preamp and the cd-writer. A simple cathode follower would do.



    turbotoy

    Posts : 47
    Join date : 2012-04-15

    Re: Connecting a CD recorder to my SP/PH10

    Post by turbotoy on Sat Oct 25, 2014 11:02 am

    Dave_in_Va wrote:
    I wasn't going to connect anything directly to the PH 10 as it is built into the SP10.

    The tape out is connected directly to the output of the input selector switch to keep the signal at line level (i.e. prior to the signal being attenuated by the volume pot of the preamp). Consequently, you are in fact directly connecting the recorder to the PH10 if you use the tape out. There is no line level buffer for the tape out in any of Roy's preamps. For inputs with low output impedance, like most CD players, this setup works just fine. That will not be the case for the PH10 for the reasons I mentioned before.

    As peterh mentioned, you need a buffer between the PH10 and the cd writer. The SP10 *may* have low enough output impedance to serve as that buffer for a recorder with a 22K input.

    Interestingly, the 2K input impedance of the Zoom is exceptionally low, even by solid state standards. However, a solid state buffer between the SP10 and the Zoom could also work.


    bluerondo

    Posts : 27
    Join date : 2014-09-21
    Location : Irvine, CA

    Re: Connecting a CD recorder to my SP/PH10

    Post by bluerondo on Sat Oct 25, 2014 2:17 pm

    Surely the 22K input will work better than the Zoom and maybe that's just good enough for car CD quality. If the Tascam has a gain adjustment (it appears it does) then this can compensate for some of the level drop. This will not be ideal for the reasons others have mentioned but maybe it's just good enough. I like the idea about a simple cathode follower. If you have a SS receiver you can use that just to make the recordings.

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Sat Oct 25, 2014 2:27 pm

    Thanks.
    I'm not a tech. I got into these nice amps because I wanted to hear the music the way it's supposed to sound. Vinyl through tubes. So I don't know how to build a buffer.
    Can I buy one and will it degrade the sound?
    Thanks again.

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Connecting a CD recorder to my SP/PH10

    Post by peterh on Sat Oct 25, 2014 3:44 pm

    Dave_in_Va wrote:Thanks.
    I'm not a tech. I got into these nice amps because I wanted to hear the music the way it's supposed to sound. Vinyl through tubes. So I don't know how to build a buffer.
    Can I buy one and will it degrade the sound?
    Thanks again.

    One example might be :
    http://www.ebay.com/itm/NEW-MK4-Indeed-Class-A-Valve-Buffer-Amp-Amplifier-electro-harmonix-ECC82EH-12AU7-/290827407364?pt=Vintage_Electronics_R2&hash=item43b6aa1004


    dmag

    Posts : 30
    Join date : 2010-10-05
    Location : North Shore,Ma.

    Re: Connecting a CD recorder to my SP/PH10

    Post by dmag on Fri Nov 28, 2014 7:42 pm

    Probably wont help.
    I had a Sony cdrw33 thar refused to play nice with my zmod pas.
    I tried a buffer and anything else I could.. The Sony finally got boxed, and I bought that Tascam.
    It is just as bad. Seems they need isolation transformers.
    The system had quite a hum as well with both cdr's. I got so p.o.'d I got out my sand preamp. .Sounds good enough. And they all work together. I hate to say it but I'll sacrifice the tube pre for zero aggravation .

    TMadden

    Posts : 99
    Join date : 2011-12-22

    Re: Connecting a CD recorder to my SP/PH10

    Post by TMadden on Fri Nov 28, 2014 8:15 pm

    Dave, here is a buffer you can connect to your tape out and then to your Tascam.
    It has a 47K input impedance so it won't load your tape output excessively. My only reservation is why they rate it's output impedance as 100K, as the LM-833N IC it uses can drive 2K loads. May be worth a shot at $35: http://www.mcmelectronics.com/product/50-14820#reviews

    audiobill

    Posts : 271
    Join date : 2014-03-13
    Location : Philadelphia

    Re: Connecting a CD recorder to my SP/PH10

    Post by audiobill on Sat Nov 29, 2014 4:50 am

    Why not get an ART Phono +, (Analog to digital converter), record to your computer, and playback that way?

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Sat Nov 29, 2014 12:00 pm

    I think I'm just going to bag the idea.
    Will the tape out of my Preamp work with a cassette deck?

    Pillo69

    Posts : 104
    Join date : 2012-04-11
    Location : Granada (España)

    Re: Connecting a CD recorder to my SP/PH10

    Post by Pillo69 on Sun Nov 30, 2014 9:02 am

    I use the tape outlet PAS preamplifier (original) to the computer and saturates the signal. To avoid this problem I interject in a potentiometer signal cable 500 K.

    bluerondo

    Posts : 27
    Join date : 2014-09-21
    Location : Irvine, CA

    Re: Connecting a CD recorder to my SP/PH10

    Post by bluerondo on Sun Nov 30, 2014 5:36 pm

    If the cassette deck input impedance is low like the other devices the same problem will exist. I think your best option is to use the MK4 buffer amp on ebay that was posted previously. It has a 1Meg ohm input impedance which would provide minimal loading, maybe use this only when you want to record. A listening test will tell you if leaving it connected will alter the sound quality during normal use. The other option would be if you wanted to try your hand at tech stuff. I don't know if there's enough reserve power in your preamp to provide enough power for one 12AU7 tube. This tube is ideal for a dual cathode follower amp which is practically the simplest amplifier, a cathode follower is used to do exactly what you need (high input impedance and low output impedance). The 12AU7 has two sections so you only need one. The power supply filament winding would need to supply either 150ma/300ma current and also about 15mA current from B+. Each amp (for R and L) would need approximately two capacitors and 4 resistors. I'm looking at page 50 of "Design and Construction of Tube Guitar Amplifiers", but I'm sure there are other circuits around. If you were willing to try this I'm sure we can get additional help from some of the users here. I envision a simple vector board with these components on it and mounted inside your chassis.

    I share your desire to keep all things "tube".
    Good luck...

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Connecting a CD recorder to my SP/PH10

    Post by peterh on Mon Dec 01, 2014 11:29 am

    bluerondo wrote:If the cassette deck input impedance is low like the other devices the same problem will exist. I think your best option is to use the MK4 buffer amp on ebay that was posted previously. It has a 1Meg ohm input impedance which would provide minimal loading, maybe use this only when you want to record. A listening test will tell you if leaving it connected will alter the sound quality during normal use. The other option would be if you wanted to try your hand at tech stuff. I don't know if there's enough reserve power in your preamp to provide enough power for one 12AU7 tube. This tube is ideal for a dual cathode follower amp which is practically the simplest amplifier, a cathode follower is used to do exactly what you need (high input impedance and low output impedance). The 12AU7 has two sections so you only need one. The power supply filament winding would need to supply either 150ma/300ma current and also about 15mA current from B+. Each amp (for R and L) would need approximately two capacitors and 4 resistors. I'm looking at page 50 of "Design and Construction of Tube Guitar Amplifiers", but I'm sure there are other circuits around. If you were willing to try this I'm sure we can get additional help from some of the users here. I envision a simple vector board with these components on it and mounted inside your chassis.

    I share your desire to keep all things "tube".
    Good luck...

    I did my buffer with 12au7 and the schematics from http://www.valvewizard.co.uk/accf.html
    ( close to bottom). It uses 1/2 of 12au7 per channel, one tube is enough for stereo.

    Now to make life easier, ebay sells zillions of buffers, one example :
    http://www.ebay.com/itm/1x-6N3-Tube-HIFI-Buffer-Audio-pre-amplifier-amp-board-with-Transformer-/321511473902?pt=LH_DefaultDomain_0&hash=item4adb93c2ee
    app. usd 55 . Needs some assembly.


    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Connecting a CD recorder to my SP/PH10

    Post by tubes4hifi on Tue Dec 02, 2014 12:00 pm

    TurboToy and PeterH are correct, the problem is that the SP10/PH10 does NOT have an output buffer, and anything connected to the TAPE OUT jacks should have an input impedance of greater than 100K. Even that will load the phono output down enough to cause a serious change in the RIAA EQ.

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Tue Dec 02, 2014 4:06 pm

    So, out of curiosity, is the "Tape out" just for a tube reel to reel deck?
    Not bitchin', I LOVE my ST-70 and SP/PH 10 (both of which continue to work perfectly...thank you Troy and Sal).

    tubes4hifi
    Admin

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    Join date : 2008-11-30

    Re: Connecting a CD recorder to my SP/PH10

    Post by tubes4hifi on Tue Dec 02, 2014 7:45 pm

    you can use the TAPE OUT jacks for anything, but it had better have a very high input impedance, or it will load down the phono stage.
    Best to add a buffer (either solid state or tube).

    dmag

    Posts : 30
    Join date : 2010-10-05
    Location : North Shore,Ma.

    Re: Connecting a CD recorder to my SP/PH10

    Post by dmag on Mon Feb 02, 2015 1:23 pm

    Any reason this is not a viable solution ? I hope so . As Bob may attest, it looks like a long winter indoors.

    I have added a Hagerman Bugle2 solid state phono preamp to my zmod PAS3 as follows

    TT to outboard phono preamp input
    Phono preamp output to burner input
    Burner output to preamp line level input.

    The cd burner can now be used with no harm to the phono board.

    When I get an urge to record,i just swap the cables at the turntable, and set my PAS to the input my burner uses.
    It seems to work great, Takes about ten seconds to swap the cables, acts as a tape loop, and has the added benefit allowing me to monitor the recording levels.

    For daily listening i use the zmod phono stage.
    I do like it better, but the Bugle is also very good.
    I have used a Yaquin buffer but it attenuates the signal too much for the burner to compensate for.
    http://www.ebay.com/itm/YAQIN-CD1-Upgrade-6992-Tube-Buffer-Processor-For-CD-DVD-make-TRANS-sound-nice-/170482642516

    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Mon Feb 09, 2015 1:53 am

    I'm thinking again about trying this with the TASCAM CD-RW900 mkII. I like dmags' idea but I don't like having to plug and unplug my turntable mostly because of a space problem and the difficulty of getting behind the gear (and no room to slide components out for access).

    Would a simple switcher degrade the signal to my SP10/PH10? Should I use anything special for this switch? I really, really don't want to degrade the sound in my living room. Keep in mind, my use for burnt CDs will only be in the decidedly low-fi Dodge caravan.

    Also I have an old Pioneer SA 520 (with a phono input and plenty of line outs) that's only hooked up to a Sirius radio that I suppose would work as well as a new buffer/pre-amp. Right, wrong?

    Remember, I'm a non-tech.



    Actually I guess "B" should go to the Pioneer (or buffer/preamp) and then to the burner.


    Dave_in_Va

    Posts : 129
    Join date : 2013-04-02

    Re: Connecting a CD recorder to my SP/PH10

    Post by Dave_in_Va on Sat Jan 30, 2016 3:18 pm

    Sorry to resurrect an older thread but I just pulled the trigger on the TASCAM CD-RW900mkII Professional CD Recorder. (See first post for URL).

    One poster said it might work, one said he had had zero luck getting this to work but most thought it would work with one of those eBay Chinese buffer amps. So I'm prepared to have to buy one of those gizmos.

    Since I originally posted, I picked up an Audio Control 520B EQ unit (old early '80's stuff recommended by deepee99) that I have between my SP10/PH10 and my VTA ST70. (It works perfectly on the rare occasion I need to tweak a freq. on an old record).

    The Audio control has a "tape out" that I'm hoping will work with the Tascam. If it doesn't, my next step would be to buy this…

    http://www.ebay.com/itm/NEW-MK4-Indeed-Class-A-Valve-Buffer-Amp-Amplifier-electro-harmonix-ECC82EH-12AU7-/290827407364?pt=Vintage_Electronics_R2&hash=item43b6aa1004

    …………which was recommended by PeterH.

    Is there anyway that I can damage my SP10/PH10 buy trying out the Tascam both directly out of the "tape" out" or if that doesn't work, going out of the "tape out" of the Audio Control EQ box?

    Here's a description of the Audio Control (takes a minute to load…)

    https://ia700400.us.archive.org/25/items/Audio_Control_520B_Equalizer_/IA_Audio_Control_520B_Equalizer.pdf

    Thanks in advance. I just don't want to chance screwing up my gorgeous sounding stereo.
    Dave

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Connecting a CD recorder to my SP/PH10

    Post by peterh on Sat Jan 30, 2016 3:53 pm

    The audio control has an input impedance of 100k ( p.29 ) so it's a border case, according to post #19
    it will load down the riaa stage.
    It wont hurt anything but sound will not be optimal.

    A high impedace ( on input ) buffer is what you need, connected to the "tape-out" of the preamp.
    The buffers output should have low impedance ( < 100k, but most buffers are in the <10k region)

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