[Eugguy]

David/Cypher Labs is probably the company that stays the most true/honest to their customers. Besides a great product, you get great service, which is almost next to impossible to find in today's society. Not a hint of arrogance or ignorance as experienced with most snobby audiophile types. I haven't been using the 720 as often as I would like. I've been just rocking the iPhone at the moment due to my schedule, daily routine. However, when I do get to plug into the 720, I am treated to sweet, rich, clarity otherwise not found in my other daps/dacs/amps.

 

[Luthus]

I'm thinking of buying the theorem to solve my portable issue with battery life constraints (disappointing moment when your source/dac/amp runs out of juice and you can't charge and play at the same time). According to Rudi's post, the er4pt does not emit much or possible any noticeable hiss, however, I use the p-to-s adapter. Can someone verify the hiss? I will verify this myself by trying out a store demo, but I'll have to make time to go to that store.

My setup intention: iPhone4s 64GB > CL Theorem 720 > Etymotic ER4PT (/w s adapter).

On another note, how does the Theorem stand against the setups below when aiming for sound quality from iems?
1. CLAS original + ALO Rx MK2(tactical edition)
2. CLAS (Tactical) + ALO Rx MK2 (Tactical)
3. Fostex HP-P1
4. CEntrance HiFi M8
5. CypherLabs Bundle (Duet + Solo -dB + Balanced Interconnect)

I know this is a big ask with lots of variables involved, but I'd like to know your opinions in comparison. Still researching but thought I'd ask the community while I'm at it.

Cheers.

I havent heard and paired With T Peos Iem , since i have sold My T Peos H-100

Theorem has hiss on BA driver iems , except on Two BA driver that i have :
etymotic ER 4 PT
Earsonic SM 64 v1 and v2

 

[Hawkertempest]

Hi,
I run iPod 160 Classic through my 720 using high quality cds" ripped via apple lossless playing through B&W P3 and P5's. I get absolutely no hiss.
I also use the same rig connected to my Cary SLP-05 connected via Silver Dragon and WBT RCA's playing through Beyerdynamic T1 600 ohm head phones, no hiss, absolutely black background........shear bliss! 
 
I highly recommend the Theorem 720 and it's battery life is amazing. Its ability to recharge my iPod as well is a huge bonus.

 

[catcherfly]

I just received some new cables from Forza Audioworks for my Theorem 720 - a copper USB cable (computer), a copper/silver hybrid LOD cable, a copper IEM cable (for T-Peos H-300), and a balanced XLR to RSA headphone cable adapter. HE-400s balanced out of the 720 may sound better than coming balanced out of Audio-GD NFB-28. Still too early for me to make comparisons but, for sure, the Theorem 720 is an incredible unit.

 

[lukeap69]

Wow, better than NFB-28, that's a good plus the Theorem. It used to be my 'desktop' DAC but since receiving NFB-1, my Theorem became my portable DAC/amp again because I think the Audio-gd is the 'better' DAC. The instruments sound more natural on my NFB-1 IMO. Having said that, the Theorem is a very capable unit even if used as a desktop DAC.

 

[catcherfly]

Wow, better than NFB-28, that's a good plus the Theorem. It used to be my 'desktop' DAC but since receiving NFB-1, my Theorem became my portable DAC/amp again because I think the Audio-gd is the 'better' DAC. The instruments sound more natural on my NFB-1 IMO. Having said that, the Theorem is a very capable unit even if used as a desktop DAC.

Despite the same the ES9018 chip, I imagine  the NFB-1 is a much higher quality DAC than the NFB-28.
 
Just to satisfy my own curiosity, I will spend some time doing more comparisons between the NFB-28 and the Theorem 720. Particularly as headphone amp/DAC combos, and then as separate DACs running out to speakers. The later will be difficult to do a straight one-to-one comparison because the NFB-28 has balanced XLR connection options and 720 only has a 3.5 mm line out. 

 

[lukeap69]

If there is a difference in NFB-1 and NFB-28 DAC's SQ, I presume it would be small. Please don't get me wrong with my post, I thought the my Audio-gd is the better performer (perhaps for my cans) and if you hear the Theorem to perform better then that is good. It is so nice that you can bring the Theorem easily to anywhere you want and give you great SQ. Enjoy!

 

[AnakChan]

Hi Theorem 720 owners. Do you have RFI with your iDevice (in my case, iPhone 6) with the Theorem 720?

 

[refault]

  Hi Theorem 720 owners. Do you have RFI with your iDevice (in my case, iPhone 6) with the Theorem 720?

 
What kind of interference do you suspect it to be?
 
I have had cellular network interference with the Theorem 720 on my iPhone 3GS and iPhone 4S on AT&T (AT&T uses lower >1000mhz spectrum frequency, if I recall correctly), but once I switched over to T-Mobile on my iPhone 4S (1800-2000mhz frequency spectrum) I only rarely encounter RFI w/ the Theorem 720 now days.

 

[PAM005]

  Hi Theorem 720 owners. Do you have RFI with your iDevice (in my case, iPhone 6) with the Theorem 720?

Hi AnakChan,
 
No problems with my Theorem 720, i did have some issues with my older CLAS - but wrapping the device in some RFI/Emi paper will help. Stillpoints does have some products in it's assortment.
See: http://www.tweekgeek.com/stillpoints-ers-rfi-killer/
 
Hope this will help you some...

 

[AnakChan]

Cheers for the response chaps.
 
@refault, I noticed it more with my iPhone 6 and didn't recall it so much with my iPad. Good point about different providers, maybe different frequencies. On my iPad I'm with Softbank and on regular LTE, whilst the iPhone 6 is with Docomo and on LTE-A.
 
I don't recall this on my CLAS -dB/Duet setup but I haven't tested that too extensively.

 

[shotgunshane]

I had RFi with the -db/duet set up. I even had to turn wifi off the touch I used it with. Besides size, that really the only issue I had with that set up. It was otherwise excellent sounding.

 

[Bopper29]

With humble iPod classic (160gb) only very occasionally. And this is amongst crowded trains and buses. Mind you, I keep my own phone in a separate pocket. My guess with iPhone 6 is that you will experience RFI but above comments seem to indicate it's variable.

 

[HowlingLung]

Looking for some input from Theorem owners.
 
I'm currently look for a portable Amp/DAC that pairs well with my iPod touch, and many of the features of the Theorem appeal to me, such as the battery life and being able to charge my iPod while listening. The two headphones I currently own are the HD 598s which I use at home and the PSB M4U 1s which I use when traveling. Do you guys think the Theorem would be a good fit for these headphones? 

 

[midnightwalker]

You won't have any issue to pair your phone and headphones with the Theorem. It has a great DAC and powerful amp.