Amp upgrade opinions

[Hakka69]

I currently have an RB 1070 powering my mains (B&W603) and a RMB 1075 powering the centre + surrounds.
I have the upgrade bug and want to get another amp.
I was thinking of adding another RB 1070 to biamp the mains, but now I'm thinking of maybe going for a RB 1080.

Is it possible to use an RB1070 and RB 1080 in a biamp configuration, or will I have level matching problems because the amps aren't identical?

How would you rank these options:

1. 2 x RB 1070 biamping mains, 1075 cent/surr

2. 1 x RB 1080 on mains, 1075 on surrounds, 1070 biamp centre

3 1 x RB 1070 + 1 x RB 1080 biamping mains, 1075 cent/surr


Speakers are B&W 603,602,601 and LCR600.

Harry.

[Clepto]

With 600 series speakers, I'd go with a good 5 channel amp for all but the mains, and a good 2 channel amp for the front L/R... (Or just go with a single RMB-1077).

[Hakka69]

I already own the RMB 1075 5channel and RB 1070 2 channel, I'm looking at upgrading the aplification to the mains.

[Kevin D]

You will see a substantial gain from going to one 1080 rather then add another 1070.

Kevin D.

[mike c]

my opinion:

bridge the 1070 rather than biamp ...

option 1: get another RB1070 to bridge both mains
option 2: get the RB1080 for the mains, then bridge your 1070 for the center

[Hakka69]

I've been doing a bit of research and it seems bridging is generally frowned upon as the distortion numbers rise considerably?? Any comments on this?Does anyone have any experience with bridging the RB1070?

I've also been reaiding about reliability issues with the RB1080, whereas the 1070 doesn't seem to have any probs??

If I go with the passive biamp option I will eventually upgrade to an active biamp system, which I assume would beat all 3 options above by a considerable margin. For this reason I am leaning towards another 1070 (also my gear rack will need major modifications to accomodate a 1080). This would also alow me to experiment with bridging the amps as suggested above.

[mike c]

bridging produces higher THD (distortion) ... but at the % rotel quotes us ... you won't hear the difference.

[soundhound]

You will see a substantial gain from going to one 1080 rather then add another 1070.

Kevin D.

I'll 2nd this.
Many of us had been there, done that, with great resullts..........

[calmac]

Bridging increases voltage output but reduces current output form memory bottom lie 'it's generally not recommended in high quality hi-fi or ht sytems.IMO one 1080 would be your best bet for sound quality improvements.
With regard to reliability issues Rotel have provided a fix , that works for this problem which can be retrofitted to all older 1080's and and new units have the circuit revisions built in.
Gordon

[mike c]

... and new units have the circuit revisions built in.
Gordon

do we have a date or cutoff when the new 1080's are immune to the fuse/12v trigger thing?

(the 1080's in the philippines, only have a 2 pairs of binding posts - therefore cannot be used as a guideline whether the unit is new or old)

[gianni]

I will bet that you probably do not want to hear this, but I have to be honest - wait until you are ready to upgrade your speakers. This will provide a much bigger improvement than upgrading from 1070 to 1080. I know it's fun to swap those black boxes but truth be told, speakers will make a much bigger improvement. The difference from 1070 to 1080 pales in comparison. Your 1070 is perfectly adequate for the 600 series.

[calmac]

Gianni , I think a personal audition should be the final arbiter as to whether the op can see value in the upgrade.A 1080 imo should still give a significant upgrade and will provide a better platform for speaker upgrading when the 1070 will definitely become inadequate.
Gordon

[apodaca]

Why is the 1080 always portraid here on these forums as the bare minimum? Nonsense! Yeah the Rotel integrated amps are crap - sure. Its all relative. Some speakers are an easy load others are not and that for the most part determines if an amp upgrade is a noticable improvement. The 600 series are an easy load even for the 1050 the 700 series OTOH are not while Martin Logans are an even more difficult load.

[Hakka69]

I will bet that you probably do not want to hear this, but I have to be honest - wait until you are ready to upgrade your speakers. This will provide a much bigger improvement than upgrading from 1070 to 1080. I know it's fun to swap those black boxes but truth be told, speakers will make a much bigger improvement. The difference from 1070 to 1080 pales in comparison. Your 1070 is perfectly adequate for the 600 series.

I don't doubt that speakers would be a significant upgrade, I would like B&W 800 series, but they are just way out of my price range so until I win the lottery I'll have to stick with the 600s.

I never did get an answer to the question about bi-amping with a 1070 and a 1080, would there be level matching problems? Anyone?