Huge Problem with my Sunfire TGA 7401

[oalbakr]

Guys really need your help on this one!

My Setup:
Lexicon MC-12HD EQ
Sunfire TGA-7401
2x Sunfire CRS3 (LEFT\RIGHT)
1x CRS-3C (Center)
4x CRM-2BIP (Surrounds)
2x TS-EQ10
Lexicon BD-30

I recently installed the system and i have the Lexicon MC-12 Connected to the TGA 7401 through Balanced XLR cables.

sound cannot be heard from speakers until i reach -40dB on the lexicon. and when volume is on 0db, sound level is too low
it doesnt feel like 400W at all!!!! for testing purposes i connected a Yamaha RX-V663 to the speaker directly. when the Yamaha is on 0dB, it gives the same output as the lexicon/Sunfire when on 0dB!!!

Something is wrong and i cant figure it out! please help

[TNRabbit]

HOLY SH!T~ 0 dB should be popping fuses & blowing up speakers!

Let's diagnose this:

1. Have you been through the menu on your Lexicon to verify the outputs/trims aren't turned all the way down? What about the output of your CDP; is it adjustable?
2. Do you have a pic of how you have everything connected on the rear of the preamp/amp?

I took this directly from your Lexicon manual online:

OUTPUT LEVELS
The OUTPUT LEVELS menu contains parameters for adjusting
CENTER, SIDE L/R, REAR L/R, SUBWOOFER L/R, and LFE output
levels on a per-mode basis.
The OUTPUT LEVELS menu is not available for listening modes that
do not accommodate multi-channel outputs, such as MONO. For
these listening modes, the OUTPUT LEVELS menu option appears
as an output-specific parameter, such as CENTER LVL.
Default
Parameter Value Values
CENTER +0dB OFF, -30 to +12dB
SIDE L/R +0dB OFF, -30 to +12dB
REAR L/R +0dB OFF, -30 to +12dB
SUB L/R +0dB OFF, -30 to +12dB
*LFE +0dB OFF, -30 to +12dB
*The LFE parameter is only available for 5.1-channel listening modes.
An alphabetical listing of parameter descriptions begins on page 5-20.

rear of Lexicon MC-12:


rear of TGA-7401:

[oalbakr]

I have tried everything!!! i double checked the connections, cables, polarity, bluray player volume. i even tried using the yamaha as a pre-amp ( yamaha RCA preout to sunfire Unbalanced RCA inputs. and im still getting the same low volume at 0dB!!!!!

[TNRabbit]

If you've verified your Lexicon processor outputs are at 0 db, it's time for a calll to Sunfire, then.

[oalbakr]

with this setup, i though i would never exceed -20dB!!! any TGA 7401 owners faced the same problem???

[TNRabbit]

I have the Theater Grand IV processor & Cinema Grand Signature amp (same as yours but older) & the loudest I've EVER had it with pair of AL-IIIs is -9 db. That's ROCKIN' the house~

I think you have some sort of mismatch going on with sensitivity levels or input impedance.

You can email Bob directly: bob dot sunfire at gmail dot com

[oalbakr]

Bob as in bob carver? Or bob as in a technician at sunfire?

[TNRabbit]

Bob as in bob carver? Or bob as in a technician at sunfire?

Bob as in THE BOB CARVER. He'll be at CarverFest in NC tomorrow, I believe:

viewtopic.php?f=141&t=12548

[BillD]

Have you tried the RCA inputs/outputs instead of the XLR inputs/outputs on the Lexicon/Sunfire?

[oalbakr]

Yup. That didn't work either

[oalbakr]

Rabbit would you kindly go into more details regarding sensitivity and input impedance.

I'm having some problems attaching the lexicon and sunfire specs. Would you be kind enough to check both specs and see if there is a mismatch.

I just can't get any sleep. Keep thinking about the problem and possible solutions

[megasat16]

I recently installed the system and i have the Lexicon MC-12 Connected to the TGA 7401 through Balanced XLR cables.

sound cannot be heard from speakers until i reach -40dB on the lexicon. and when volume is on 0db, sound level is too low
it doesnt feel like 400W at all!!!! for testing purposes i connected a Yamaha RX-V663 to the speaker directly. when the Yamaha is on 0dB, it gives the same output as the lexicon/Sunfire when on 0dB!!!

Something is wrong and i cant figure it out! please help

I think it's normal that you didn't hear anything till the volume level on the lexicon reach -40dB. It's coz it's probably configured to THX reference levels or it may be simply configured by a previous owner (if you didn't buy it New) for lower output levels.

If you haven't already done so, download the user manual from here and read through it. Then, reset it to factory setting and adjust output volume as described in the manual and adjust speaker distance to 0 if it's not set at 0 after factory reset.

Also, if you are using 2 channel (stereo) setup with full range speakers, you want to send LFE to both the front speakers and to the subs if you have a sub connected to the sub also.

http://www.lexicon.com/downloads/mc12/M ... v1_Eng.pdf

[oalbakr]

All equipment are brand new and on factory settings.

[TNRabbit]

Sunfire TGA-7401:

Damping Factor 150
Hum and Noise -118dB, A-weighted
Sensitivity Balanced(for rated output) 0.95Vrms
Sensitivity Unbalanced(for rated output) 1.9Vrms
XLR Input Impedance 10kohms
RCA Input Impedance 24kohms

Lexicon MC-12HD

Output Level
• 150mVrms typical, 6Vrms maximum (RCA connectors)
• 300mVrms typical, 12Vrms maximum (XLR connectors, MC-12HD Balanced only)
• Maximum value with full-scale input signal and volume at +12dB
Output Impedance
• 100Ω in parallel with 150pF (RCA connectors)
• 50Ω in parallel with 150pF (XLR connectors, MC-12HD Balanced only)

OK, I not exactly certain how to interpret these differences; perhaps someone else can tell you specifics. It appears the output level on the Lexicon is good but not certain where the 10 & 24 kohm values work with the inputs impedance on the Sunfire. Anyone?

[oalbakr]

i have been trying to get the specs of the sunfire TGP-401 to compare. but unfortunatly, specs are not complete and could not find usable info.

BTW, is it normal to hear a faint electrical noise coming out of the sunfire's Tracking downconverter board? the strange thing is that the electrical noise seems to be related to the content being played. (Ex. i have A joe Satriani concert playing on my DVD player. and when listening carefully to the sunfire, i can hear the same music being replicated on the downconverting board but as an electrical noise)

is that normal?