TX103 and Shelter 901

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dselwa

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TX103 and Shelter 901
« on: 20 Sep 2006, 07:26 am »
Hi John,
Been thinking of getting a Shelter 901. Wondering if its a good load for the TX103(silver or copper)?

Wright-sound WPL10V

Dennis

John Chapman

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Re: TX103 and Shelter 901
« Reply #1 on: 20 Sep 2006, 12:43 pm »
Hello!

That combo should work out just fine. There was a time about a year or so back where it seemed half the MU step-up sales were to Shelter 901 owners! We used a 501 at the last VSAC show and it was a really nice cartridge too.  For silver  vs. copper we really should discuss your system's ballance on the phone - please call the shop when you have time or e-mail your number and a good time to call.

Many Thansk!

John

violinist3

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Re: TX103 and Shelter 901
« Reply #2 on: 27 Sep 2006, 05:07 am »
Hi John,
You have been saying several times that the silver may not be for systems that have lightweight bass. I was wondering if cartridge loading enters into the equation? I read Salvitores coments about his ZYX Universe cart. The rated resitance is 8 ohms. He had trouble loading the silver secondary with less than 15K ohms. At 400 to one impedance step up he would need 3.2K at the secondary to get a good match. He found that 10K caused so much attenuation that he didnt have enough gain.Soooo i have been thinking that maybe his cart isnt a good match.For instance the Denon DL103's resistance is 40 ohms and would probably be a very good match since 40 times 400 equals 16K impedance. I am interested in the Shelter 901 (20 ohms) and it seems a likely candidate for the silver. Any 901 owners that had good solid bass (with no roll off) with the silver?


Dennis

John Chapman

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Re: TX103 and Shelter 901
« Reply #3 on: 27 Sep 2006, 06:56 pm »
Hello!

Loading for sure has a role in getting the tonal balance of the system just right - that is why I made loading swaps easy on the MU's. With many setups you need to solder to swap loads and you are not likely to try alternate loads like that...... Loading is a useful tool to fine tune the system but don't think of it an an EQ setup - as an example you can't just load down really low to pump up the bass without affecting both the gain level and the top end extension at some point. Loading is really meant to find the load that the cart is happy at and then to skew a bit either side of that to tweak system balance. It won't be useful for making large changes in system balance.

I don't think looking at the cartridge and loading is really the answer when it comes down to silver vs copper. In that case I think the rest of the system - speakers in particular - will be the overriding factor. Loading can tune the tonal balance but I would not rely on it to skew balance in a big way - ie. to make the system do something it naturally does not want to do. The decision tree goes something like this:

1- If $ are a big factor then forget that silver exists.

2- If your system has a light weight bottom end (like some single driver systems as an example) then forget about silver. The natural balance of the coppers in the low end will better suit the system so why fight that.

If neither of those are the case then silver is an option so call and we can discuss it. 

About the loading questions you had in particular:

1- Loading the cartridge to exactly it's internal impedance is a nice idea. Often in high frequency transmission lines you MUST impedance match like this but it is less applicable to cartridges and it is not a magic formula for correct loading. First there is the gain issue - at that loading you WILL piss away half the signal across the internal imp of the cartridge. Many times if you have lots of gain you could get away with this but in Arthur's case he needs the gain so it is just not an option. Also for MANY cartridges this low a load just plain does not sound best.  Lots of customers land in the 60 to 200ohm range for loading and that is clearly well above the internal impedance of the cartridge.


2- Internal Impedance is an important spec and in particular it tells us what ratios are likely to work best. To run 1:20 mode I like to stay below 20 ohms to 30 ohms internal impedance or so as an example. When the impedance's get up high you don't leave much of a window open for loading at 1:20 ratio so I tend to go 1:10. Same goes for cart manufacturers recommended loads - if the recommended load is 100 ohms 1:20 mode leaves very little room to play with loading up above that load range.



There I go again - making it sound more complex than it is! Most times the ratio and copper or silver quickly become apparent by looking at the specifics of the system and the cartridge used. Bottom line in my mind is to choose silver vs copper and then choose a ratio and finally to play with loading using your listening tests rather than spend time trying to pick an ideal load ahead of time. 

As to your final question I can see no reason silver at 1:20 mode would not work well with the 901 in a typical system.

Many Thansk!

John

acoustat6

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Re: TX103 and Shelter 901
« Reply #4 on: 26 Oct 2006, 02:03 pm »
Hi John, I too have a Shelter 901, mine is partnered with a Hagerman Trumpet phono stage. I just bought a used pair of TX103s. I will be using a passive preamp for a total gain of 64d. 44db Hagerman plus 20db TX103. What  load (resistors) do I use for the transformers? Does this affect the load on the Hagerman and therfore on the passive preamp? Any other suggestions or  thoughts with this common combination?
Thanks,
Bob

John Chapman

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Re: TX103 and Shelter 901
« Reply #5 on: 26 Oct 2006, 10:44 pm »
Hello!

Your system is sounding a bit familliar - I have a Haggerman Trumpet here myself. That combo should work out very well - although if you have a resistor passive I'd keep those cables really short if you can.

First - the loading at the cartridge has NO affect on the output side of the Trumpet. That output is determined by the circuits in the phono stage.

The secondary (phono stage side) of the TX103's always 'sees' the 47K load inside the trumpet. Without adding any load resistors to this you get a cartridge load of 470 ohms at 20dB of gain (1:10) and 120 ohms at 26dB of gain (1:20 mode). Adding load resistors will lower this load down from those points.

I am a big fan of playing with loading. There is not much chance of figuring out the exact loading that will suit you and your system ahead of time by analysing the numbers and specs - although that can indicate the range you are likely to land in. Also it is much less fun doing the math than it is just listenning!

If you have RAW TX103's then you'd choose to wire them at 1:10 or 1:20. The 901 could drive either mode and it can be changed so I would not get hung up on which mode to use at first. Unless you amp/speakers are quite in-efficient likely either mode would give you the volume you need.

If you could describe how the TX103's are packaged (if at all) and what ratio you will start with then I can suggest ways to setup to make it easy to swap loads and suggest some values to play with.

Thansk!

John







acoustat6

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Re: TX103 and Shelter 901
« Reply #6 on: 27 Oct 2006, 01:15 pm »
Hi John, Thanks for your reply. My passive pre is resistor based, Goldpoint ladder type attenuators. I will try to keep the cable short, though right now I am looking at 4 foot cables from the Hagerman to the Goldpoints. The transformers are Bents very own MU copper. They are about 3-4 weeks old, the gentleman bought them new and thought they did not work in his system. I just bought the Hagerman Trumpet and put it in my system yesterday and will receive the transformers today. I listened last night with the 44db of gain from the Trumpet and it was very close to enough gain. My Lehmann Black cube has 66db of gain and is more than enough. I listen to ALL LPs at the SAME volume control setting. I only listen to vinyl. So where do I start with the loading as I have the resistors that come with the transformers? I did notice that there is a bit of hum from the Hagerman, what should I look for as the cause to this? Cables, positioning, nearby power cords? Can it be very quiet? I have read that this can be an issue. I am really looking forward to hearing the MUs, they look positively great and I have heard such good things about them and your company, keep up the good work!
Thank you,
Bob

John Chapman

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Re: TX103 and Shelter 901
« Reply #7 on: 27 Oct 2006, 01:33 pm »
Hello!

The MU will make it easy to swap loads. I would start with no extra load on the MU. Listen like that for at least a few hours. After that swap in the load for 100 ohms and then just play from there. You don't need to power down to swap loads - just turn down the volume since as you touch the terminals you can induce a bit of hum and turning down the volume will eliminate that.

My Haggerman Trumpet is very quiet really. I find hum is mostly grounding related in phono front ends. Sheilded cables are usually needed from the arm to the step-up or phono stage as well. The MU step-up will likely help in a round about way - since you will be turning the level down to get the same levels you'd have now you'll reduce noise overall.

Start with the arm/table grounded at the phono stage - as it likely is now and ground each MU can to the phono stage too. That is quiet most the time.

Arn from Goldpoint is a great guy. The 4' cables to the passive will not be an issue - it is the cables after the resistor based passive that should be kept as short as you can. Sounds like from your other testing you'll not have any issues with gain at all.

Should be fun and please let me know if I can help as you get into your testing.

Many Thanks!

John

acoustat6

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Re: TX103 and Shelter 901
« Reply #8 on: 27 Oct 2006, 02:32 pm »
Hi John, I just now received the transformers. They are absolutly drop dead gorgeous! I have the resistors and the instructions on cartridge loading. I will keep in touch over the weekend and let you know how things go.
Thanks,
Bob

acoustat6

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Re: TX103 and Shelter 901
« Reply #9 on: 7 Jan 2007, 02:57 pm »
Hi John, Well its been more than a weekend, but that's just not enough time to evaluate changes and to even get things set up properly. I very much enjoy the MUs (they are beautifully built and a joy to look at and handle, vey nice indeed), the Hagerman Trumpet, shelter 901 combinatin works very well together. I have for now settled on 36 ohm loading. I now need to get a feel for it there, and I am pretty sure this is close if not correct for my system. I was having a difficult time getting system synergy/volume matching set in the system but now it is very close. The system is very quiet and dynamic with well defined and articulate bass with a nice smooth top end.

I am currently using a resistor, ladder type, passive preamp from goldpoint. in my own diy case. I have been reading with interest the TVC passive preamps that you offer. I think the TAP is the cats meow but it is out of my price range. I only need one input and output, dual mono, no switching , RCA in and out. And I do rather like the digital read out volume setting. I would like to do it as a DIY to keep the cost down, unless you have a ready made unit or kit like this. I would like to know your thoughts on my different options for this and any other things I need to be aware of or info I may be able to read to help me in my decision.
Thanks,
Bob

John Chapman

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Re: TX103 and Shelter 901
« Reply #10 on: 11 Jan 2007, 03:02 pm »
Hello!

Just back from CES - I am sorry for the delayed reply.  Thanks for the info on the Shelter loading. I only get to play with a small number of carts here myself so it is really helpful to get feedback from customers about what loading is ending up best with the MU step-up. 

A FLEX kit would be the way to go for the TVC pre-amp. Still uses the S&B TVC's like the TAP - just a few less features and a few less steps. It can easily be made Dual mono - although you can not do the motorized remote with a dual mono config - that gets a bit weird......The display is specific to the TAP system so the cost jumps up a lot to make that leap - from the description of the unit you'd want the FLEX would likely work out great.

Since you run a resistor passive now you already have answered most of the questions in your system - like gain, etc... I don't recomend the FLEX as a first DIY project - it is a bit finicky to wire the TVC to the switch - but if you have built some stuff before and you understand the basic wiring then you should be fine. Alternately I often build them for folks here for not too big a charge. Just E-mail or call and we could work out those kind of details. 

Thansk!

John

acoustat6

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Re: TX103 and Shelter 901
« Reply #11 on: 12 Jan 2007, 03:34 pm »
Hi John, Thanks for the info. I don't know how I did not see the FLEX kit on the site. I was probably too engrossed at looking at the TAP to notice and I have seen plenty of references to the TAP but not the FLEX. Sorry I asked such an obvious question. Sometimes to hide something just put it in plain sight! I will review it and let you know.
Thanks,
Bob