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View Full Version : Attenuation of TP help where are the jumpers?



jaysung
2007-11-09, 10:37
Hello,
opened my tp yesterday to see where attenuation is located and how it actually works. Now I am blind and found a structure right south to the rca connectors that faintly feels like an ide connector with too few pins. There are two prominent structures to both sides of the pins. I think there are 2 time 5 of such pins.
What am I supposed to move and what can I break by pulling at the wrong tiny bits of the mainboard?
I need a verbal explanation where exactly the relevant bits are. I could guess but then again I don't want just be trying until I tear something apart.
Thanks
Jeronimo

Fifer
2007-11-09, 10:53
Owners Guide, p24 (index says 23 but the detail and photo are on p24). It sounds like you have identified the correct jumpers (near the rca connectors).

jaysung
2007-11-09, 11:04
Yep, read the section in the ownersguide. Problem is it doesn't state where exactly the jumpers a set for 0 -10 -20 -30db.
Consequently I don't know if the structures standing out at both sides are jumpers set onto pins or anything else. If the where anything else pulling at them to remove them might not be a good idea.
The jumpers are arranged in a left to right sort of way. That means there are two rows of jumpers running from beneath the left channel to the right.

Fifer
2007-11-09, 11:17
There are six pairs of pins (three for each channel, left and right) and two jumpers (one for each channel). At the default setting (the two outside pairs jumpered), there is no attenuation. Moving each jumpers in to the next pair provides 10bB attenuation, the next pair 20 dB and the centre pair 30 bB attenuation. It's arranged as below:

0bB 10bD 20dB 30 dB 30bB 20dB 10dB 0dB
LLLLLLLLLLLLLLLLLLLL¦RRRRRRRRRRRRRRRR

Does that help?

jaysung
2007-11-09, 11:24
Yep, helps. Definitely. One thing to clarify though. The jumpers are not of the sort we know from ide drives are they? The are much bigger standing out by 1/3 inch or so. Right?

Fifer
2007-11-09, 11:28
I have to confess that I don't know. I haven't taken the lid off my Transporter. I'm going only by the detail in the picture. I'm sure someone else will jump in to confirm soon

Fifer
2007-11-09, 11:33
jaysung, I just read your post properly. The jumpers have 'handles' on top which make them stick out above the pairs of pins. 1/3rd of an inch seems about right. You just pull them up by the handle then place them on the pair which give the attenuation you want.

Mark Lanctot
2007-11-09, 12:57
There's a photo here which I'm consulting: http://photos.lam.ws/gallery/1930618/4/98134925/Large Obviously it doesn't help you, jaysung, but it may allow someone beside me to describe it better than I can.

Anyway, the jumpers are the same used on new motherboards, finger-friendly jumpers with extended handles. The handle is narrower than the base of the jumper.

It probably would feel like an IDE connection, just a row of pins. The jumpers are installed from the factory at the extreme left and right.

It should be very close to the back, there are two solid-state caps to the left and right of the row. Just behind them is a row of surface-mount resistors.

jaysung
2007-11-09, 14:41
Hello,
Thanks to you both. One question came to me when tinkering arround.
What if I set 10 and 20db at the same time for the same channel. Would I get the average i.e 15db for the power traveling across two resistors?
I used 20db attenuation and still it would wake my daughter or blow my ears when I turn my amp to 0db.
Also strange:
tp at -45db and amp set to 0db is not as loud as
Amp at -45db and transporter at full volume.

Anyway, the reason why I experiment is that I have heard an Audionet poweramp m1v2 recently. It sounded far more alive and present than the Marantz even over xlr. When I bought the tp and the Marantz amp I thought xlr was to be used when it is available. Now I see that this might be a false generalisation for the Audionet m1v2 only has rca connections. I am somewhat confused now.

Fifer
2007-11-09, 14:46
I don't know jaysung, but I doubt it. Sean would be able to advise better.

SuperQ
2007-11-09, 18:21
Hello,
Thanks to you both. One question came to me when tinkering arround.
What if I set 10 and 20db at the same time for the same channel. Would I get the average i.e 15db for the power traveling across two resistors?
I used 20db attenuation and still it would wake my daughter or blow my ears when I turn my amp to 0db.
Also strange:
tp at -45db and amp set to 0db is not as loud as
Amp at -45db and transporter at full volume.

Anyway, the reason why I experiment is that I have heard an Audionet poweramp m1v2 recently. It sounded far more alive and present than the Marantz even over xlr. When I bought the tp and the Marantz amp I thought xlr was to be used when it is available. Now I see that this might be a false generalisation for the Audionet m1v2 only has rca connections. I am somewhat confused now.

I don't think you can use more than one jumper per channel at a time. I could be wrong, I don't know how it's wired.

The jumpers don't change the XLR connection.

I would get a SPL meter and verify level when comparing two amplifiers.