Aadams

Page 5 of this link contains the published AR impedance curves http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_manuals/ar-lst_manual/

You are getting good advice from Giorgio. The tweeters appear to be later versions that do not blend at the crossover point without the capacitor and resistor. They may be the 8ohm version but I have lost access to my reference guide and cannot check the number. The 2500 cap is there to protect your amplifier from extreme low impedance. All of the caps except the 2500 are Sprague Compulytics which have proven to be durable and seldom need replacing. The 2500 appears to be an ICC Royalitic which was also decent and unlikely to be out of tolerance. The fuses are critical and can create audible output issues as they deteriorate with age. You should use new fuses of the same type.

Those are well preserved specimens. No restoration needed or recommended. They are so original that any work to improve aesthetics would depreciate the dollar value.

Highly rated by Julian Hirsch.

New 16 ohm pots are available. For the resistors you can use long wire leads from the lpad and also the resistor if you choose.

The player helps you manage the files, and reads and prepares the file for transport to the DAC. It should not affect sound quality except for bugs that interrupt the continuous flow of data. Yes Itunes is error prone and careless with artwork that is not of Apple origin. I still buy some CDs and use itunes because Apple has a vast library for discovering new music, ALAC works and it makes wireless streaming at cd quality simple. I listen to specific music selections. If I were building playlist streams by different categories I would not use Itunes. When Apple Music becomes available on W11 I will purchase a new DAC, probably a Schiit, and compare HI Res streams to high quality CDs to see what I may be missing.

Nor am I an expert. The newest Schiit DACs have on board Schiit proprietary firmware that eliminates the need for USB drivers IF you use W10, 11, MAC OS or any LINUX that is UAC2 compatible. New Schiit designs will not work with any OS that is not UAC2 compatible which means your NAS will probably never work directly connected to the Bifrost, unless Synology makes their product UAC2 compatible. I surmise that your "old Dell" is W10 or 11. Reading about the differences in Bitfrost and Uber Modi I am not surprised that you are hearing better sound. What player are you using. I am still on Itunes awaiting W11 Apple Music.

The USB is disabled because of sometthing Schiit did? Are using a MacOS or Windows Thanks

Sometimes you can’t make the music louder than the noise and keep it enjoyable. This post is about silence as a musical effect and degradation of the musical effect by noise. . As an example, the most popular classical musical work in the English speaking world, according to annual broadcaster polls, is “The Lark Ascending” by Ralph Vaughn Williams. It is a dreamscape featuring a solo violin, against a lilting string orchestra accompaniment, evoking scenes of dewy grassed meadows in early morning sunlight. Rewritten in 1920 , for a small orchestra, it was expected to be heard live in a quiet performance space where visual cues combine with sound to enhance the delineation of soloist and orchestra. There are two performances going on, the delicate violin out front and the larger group behind needing to be heard while never upstaging or engulfing the central voice. Most of the recordings before the digital era failed to capture this effect, primarily because, before digital, all recording mediums had inherent noise that was as loud as the softest violin note. I know of perhaps one remastered analog version that is an exception. The featured solo violin in this work often plays against silence. In newer DDD recordings, like the Naxos, the violin can be heard against a dead quiet background when listening from 2 meters, even with high gain settings, while the string accompaniment remains in proportion and never overpowers the solo violin. In older recordings captured in analog, the violin is somehow boosted to stay above the noise floor but this causes the sound of the orchestra and sometimes the solo violin, to get too large and out of proportion; Not enjoyable if you have an expectation of better realism. The ARGO ADD recording (above) is of this latter variety but its deficiencies, from an audiophile perspective, have not stopped it from being one of the two most popular versions of this work in the Classical Music Broadcast business. The other recording is even older. I am sure either sounds ok in a car moving over the road. The work ends with about 2 minutes of solo violin. If you are listening to the Naxos performance the violin gradually dissolves into silence near its highest musical pitch. In the ARGO you can hear the solo violin against a low pitched hiss that is the inherent noise of tape recording in 1972. The hiss is always present when the violin is playing alone. This music demands silence for you to be drawn in completely. The loudest sound at your listening position should be your tinnitus or breathing. If you hear amplifier hiss/fans, appliances, lawnmowers, household activities or HVAC vents , the effect of silence is wasted. Recordings of “The Lark” are numerous and all of them in some way serve as a practical noise floor test for home music systems and listening space. There are other examples.

Thanks. You using Windows or Apple? Did it plug and play out of the box using USB without installing drivers?

It would help you provide a photo of the AR3f speaker with the missing switch.

Did you install the parallel resistors on the L Pads? They don't appear in the photos.

This is good info. I plan to have a hi res equalizer BEFORE this conversation occurs.

Does anyone here have an informed opinion on Schiit products and customer service? Does anyone here use a Schiit Modius E DAC?

On review I noticed you don't have a resistor on the mid lpad. I am pretty sure this would create an imbalance as well. You should have a resistor on each lpad to be very close to the original pot performance. Without resistors the drivers are a bit shouty and do not respond as intended when adjusted as opposed to 16 ohm pots.

Your connections appear correct including the resistor on the pot and your tweeter appears healthy. The tweeter in the 2ax only operates above 5000hz through the crossover, above the range of any fundamental music note. The midrange unit begins at around 1500Hz and parallels the tweeter above 5k until it reaches its natural upper roll off. Are you sure what you are hearing is a tweeter problem and not a weak mid ouput? Aadams You could bypass the resistor on the lpad. You will get more tweeter output within the correct tweeter band. If you are still hearing muted output it is the mid.

I purchased the above 2004 release of this 1981 recording , which contains mostly organ tracks, for the orchestral music alone. I did not realize until recently the bonus pipe organ tracks contain some outstanding demonstration quality music that will challenge 12 inch ARs. Specifically, the Couperin “Chacone in G” and the Widor “Toccata Symphony 5” are first class recordings and performances. There are hundreds of recordings of the Widor work but it is hard to find another with equivalent quality of presentation. To hear what I am hearing you will need a CD, SACD or a lossless FLAC or ALAC file. The AAC and MP3 versions are not good enough. Vinyl is an option since all the music on this cd was originally mastered for vinyl but issued as two different recordings.

The only thing I would ad to JKent's post is you must be logged in to see the message button when you click on @RoyC

"Looks like what you called spider is loose,not sure how to shim it,and glue it, any exacting instructions available " There are plenty of examples of hinged back dust covers and shimmed voice coils on this site but not detailed instructions for reattaching fiber spacers on the cloth surround woofers. It is not difficult if you have the patience, materials and tools but if you have never done any woofer repairs this is not the driver to start on, mainly because replacements are scarce. Recommend you message @RoyC .

Based on your description, this thread, below, explains and illustrates how to repair your most likely problem. If you are new to this, read the entire thread and understand it is important that you shim the voice coil without ruining the dust cover as mentioned in the final post. If you prefer professional repair contact @RoyCusing the forum private message function. If you want to DIY with forum help, be ready to supply images of your speakers. Good luck. Adams

The short answer is yes. If the wire is disconnected at the tweeter dome contact @RoyCor @Chris1this1 for repair. If the break is between the dome and the terminal post you could try it yourself. Personally I would have Roy or Chris do a complete rebuild. Those particular tweeters have a serious drop off in performance after 50 years but they are the correct and best tweeters for the Classic ARs when restored. Adams

I have been trying to find a better or perhaps best recording/performance of Saint Saens 3 (Organ Symphony) and came full circle to my previous favorite in a different form. Out of four different orchestra recordings I have a new top 2.

DMAC Congrats. Those appear to be nice, slightly worn but uncorrupted examples. You are probably aware there are several very good 2ax restoration threads on this site. If you have specific questions you should ask. Adams

CR 7 vs CR 75 Tweeter swap doesn't look practical

I have CR 65s and 75s. The 75s are a CR7 with the Kortec tweeter and a bit better cabinet. For the money any of the CR series in good working order will be very hard to outclass with a modern two way ported speaker using comparable woofer size. The CR 8x, 9x are pretty rare these days.