giovanni56

In 1969 it happened to buy a pair of Ar3a with Alnico woofers, both with smooth and corrugated cone; it was difficult to notice the difference on the woofers, because the frames were glued and removing them would void the warranty. The engineer Gianfranco Maria Binari (later editor of SUONO STEREO HI-FI), in 1969, bought a pair of Ar3a, with a woofer in corrugated cone and the other smooth; he noticed it, because with a flashlight he illuminated the woofers through the front cloth; later he was able to get a pair with both smooth woofers from the seller.

I'd be curious to measure the R of the bracket that's part of the filter wiring, which is under the woofer's low pass inductance

16 uF va a 32 uF ?? I don't understand, with the switch in INCREASE, C1 and C2 are put in series and in this case, the capacitance is halved and becomes 8uF. Am I missing something?

In realtà, quel valore non è Fs ma Fc; tutti questi dati sono relativi al woofer installato nell'altoparlante e collegato al filtro crossover. Quindi il Qts è il Qtc, Qes è il Qec e così via. È anche evidente dal titolo, AR3a (European).

The spiders are fine; after the refoam, I checked the T&S parameters, all ok.

Everything made in Romagna, 😎

The capacitors are original Sprague, but the wiring harness wires are not original. The wiring harness has been redone. The AR10's are among the earliest produced, they have the external protection fuse next to the input terminals.

They sound very good; in my opinion, they are tops among the various Ar6 models

Restauro Ar6

Ar3a con tweeter ricostruito installato. The foam, unfortunately, is not 5/8". However, in my opinion, they sound very good.

Qts 0,025 ????

A prototype of Ar10Pone with slide selectors, was sent for testing to SUONO STERO HI-FI magazine in 1975. The test and measurements of the loudspeaker was conducted by engineer Renato Giussani (later ESB 706 designer), who reproduced, in the crossover filter scheme, the high pass of the tweeter with the 8 uF capacitor; by the way, the 8 uF value is also reported in sheet 15 of the spare parts list issued by Acoustic Research and indicated as spare part for the AR 10 (see attachments), part list 830025.

If I am not mistaken, the light hazel dome tweeters, which do not have ferrofluid, in the very early versions of Ar 10 Pi One (the ones with slide switches), had the high pass filter with 8uF capacitor and 0, 1 mH inductance, while all later versions had the 10 uF capacitor; Roy, could you kindly give me a confirmation about the tweeter and the 8 uF capacitor, thanks

Tweeter Ricostruzione AR3a: 1) Apparecchiature mobili e gruppo magnetico 2) Misurazione del peso dell'equipaggio mobile rotto 3) Misurazione del peso dell'equipaggio mobile rotto 4) Misura di R 5/6) Tweeter completato e cablato 7) Controllo e verifica centratura 8) Misura dell'impedenza e parametri T&S

Thanks

Thanks

Thanks

The moldings glued, but are also, embedded inside a milling cut in the thickness of the panels.

Se il ferrofluido è in condizioni normali, il tweeter che ne è dotato dovrebbe avere una risposta in frequenza più lineare e un'impedenza di picco più smorzata a Fs per una migliore compatibilità con il filtro e una maggiore tenuta in potenza. Se non sbaglio, i tweeter a cupola nocciola chiaro, che non hanno ferrofluido, nelle primissime versioni di Ar 10 Pi One (quelli con interruttori a scorrimento), avevano il filtro passa alto con condensatore da 8uF e induttanza 0, 1 mH, mentre tutte le versioni successive avevano il condensatore da 10 uF; Roy, could you kindly give me confirmation about the tweeter and the 8 uF capacitor, thank you.

Ar3a and Ar10p are difficult load speakers for amplifiers, low impedance modulus and large phase rotations (impedance argument), they need stable amplifiers, capable of delivering undistorted current and power. For mine, I use an Adcom GFA555 and an Adcom GFA555II

A pair of Ar3a that I have restored; every time I listen to them they amaze me with their natural and musically magical sound.

It seems to me that the first cream white dome tweeters, installed on the Ar10 and Ar11, did not have ferrofluid, but only the following ones with the dark gray dome, is that correct?

My Ar10p

In my environment and according to my tastes, the setting I prefer is 4p on the woofer, -6db on the mid and 0db on the tweeter