@TheMiddleSky posted impressions between Jot 2, Topping A90 and Singxer back in pg. 123.

Owned both amps at the same time...but ultimately decided to move on from the Rebel because my preference is for a fully balanced setup. 1. Not really. It runs on the warmer end of neutral but very clean amp overall. 2. Low Gain for IEMs, has a preference towards SE or wants a boutique amp...

I use low gain on my BF2 / Jot 2 combo. Running my S2s via 4-pin XLR out and it has been more than sufficient. Despite being 300 ohms, I find that they are quite easy to drive...my volume dial is barely past 9'clock.

Going to get a lot of flack for this but in my opinion, I'd save your money. I recently sold the Piety and also had a Rebel Amp in the past - both paired with an OG BF2. These amps were touted by many to have "tube like" characteristics but in the end...they are still solid state. Having tried...

I just have a generic 4-pin XLR Hart Cable that I had from my 650s. Since I use the S2s daily now, the stock S2 cable is now on my 650s. I use the 4.4 mm stock cable and then have a 4.4 mm female to 4-pin XLR. https://hartaudiocables.com/collections/sennheiser/products/hc-5-dual-senn

Just wanted to chime in here before we get in trouble again for bringing up the NDH30 in the 660S2 thread. I was in Japan last week and had the opportunity to demo the NDH30 at the venerable e-earphones store. They had it paired with a HDV820. While not the ideal conditions, I am a believer...

@FiiO

The Lokius does have vent holes. Coupled with posts from others regarding potential interference, it may be good practice to have Lokius separated from a Jot 2 / BF2 stack. As always, YMMV.

Do they have the filters? Or are these the earlier versions?

Great deal at $75! Curious to know what audible attributes made you like the 650 vs. 6XX. My understanding is that everything should be the exact same between the two.

I use an iPhone 14 Pro on iOS 16.5.

WTB - I am looking for a pair of 64 Audio U4S if anyone is looking to move on from a set. I am located in Canada but have a shipping box in Niagara Falls, NY for CONUS shipping. Paypal G&S preferred but not required. Thanks!

Yes, I have had 1.5 for a while. It is more about the implementation of software and lack of improvements to the app. For example, constant connection issues, where the UTWS5 does not communicate with the app. Further, the EQ presets do not save and I need to do it manually each time. There is...

So I have to ask...based on your journey with Senns, are the S2s finally the Senns you'll keep or are you still looking to sell and move on?

Thats great and all, but what is @FiiO doing to improve integration with the mobile app? Its great to keep coming up with new hardware but I would implore that the software integration is vital to a product targeted to audiophiles. While the normal consumer would not care about EQ or filters...

Looks like someone else from an earlier post tried the ZMF pads with the S2 and didn't like it. Granted, the replies said that perforated ZMF pads might be better than the solid ones. See link below. https://www.head-fi.org/threads/sennheiser-hd-660s2-thread.966685/post-17571276

IMHO, if you don't need a TWS solution...I'd stick with the Q5K for mobile needs. The FiiO app is bag of crap compared to the features and functions on the Qudelix...and there is no support / updates once FiiO takes your money. Just a horrible user experience in general...each time I use it, I...

https://www.reddit.com/r/AVexchange/comments/13e0lo5/wts_usami_h_sennheiser_hd660_s2_w_paypal/?utm_source=share&utm_medium=ios_app&utm_name=ioscss&utm_content=2&utm_term=1 A used pair going for $420 shipped in the US if anyone was interested.

I was eyeing the MM2 but last I checked it was still 10-12 weeks out. Glad to know its back down to 2-3 weeks now.

Chances are that it is a 2 if there are 3 front toggle switches but I would ask the seller to send a photo of the serial number tag on the bottom. It would be another way to confirm whether its really a Jotunheim 2.

I've also raised the EQ being lost issue with FiiO before but was told I was the problem...and their engineers could not reproduce the results. Interesting to hear that others have found the same issue in everyday use. The EQ issue, random dropouts, units not charging, and frustratingly horrible...

Does the new ifi product give the option to EQ? if so, that might be deal-breaker for me. I would move on from the @FiiO product line in a heartbeat.

The visualizer alone is makes the RME worth the money ;)

I know you've shared this multiple times but what does removing the inside foam to expose the driver do? Does it increase treble?

Hoping that adding the Bifrost to the chain will be the combo that wins you over in favour of the S2. Regardless, I am enjoying the account of your journey with the S2s, whether good or bad.