Heathkit AR-1214

I picked up an early 70's Heathkit AR-1214 receiver today that was in pretty mint condition. The pots needed to be cleaned out to remove the static build up. The tuning is a bit off on the FM dial but every station comes in clear as a bell.

Right now it is powering my Audio Spec Perseus speakers in my office and I really like the sound stage, surprisingly deep and warmth. Next I will try them with the Pioneer HPM-60's.

The Heathkit AR-1214 specifications are as follows:

Amplifier Section:
Power Output:  15 Watts RMS (8 Ohm Load), 20 Watts (4 Ohm Load)
Power Bandwidth:  5 Hz to 30 kHz (< 0.5% THD)
Frequency Response:  7 Hz to 100 kHz (+/- 1 dB)
Harmonic Distortion:  < 0.5% (@ 15 Watts output)
Damping Factor:  > 30
Hum and Noise:  -60 dB
Channel Separation:  55 dB

FM Section:
Tuning:  88 to 108 MHz
IF:  10.7 MHz
Frequency Response: 20 to 15 kHz (+/- 1 dB)
Sensitivity:  2 uV
Selectivity:  60 dB
Image Rejection:  50 dB
IF Rejection:  75 dB
Capture Radio:  2 dB
AM Suppression:  50 dB
Harmonic Distortion:  0.5%
Inter modulation Distortion:  0.5%
Hum and Noise:  60 dB
Spurious Rejection:  70 dB

AM Section:
Tuning:  535 to 1620 kHz
IF:  455 kHz
Sensitivity:  100 uV
Selectivity:  40 dB
Image Rejection:  75 dB
IF Rejection:  60 dB
Harmonic Distortion:  2%
Hum and Noise:  35 dB

JPW AP1 versus Mission 700S

A little comparison on the these two speakers for the past few hours.

JPW is a little tighter on the bass due to the acoustic suspension design, the sound stage is also a little more laid back. The high end is the same as the Mission 700S.

The Mission 700S is a few db's louder and much more mid range forward, the bass not being as tight. The Missions surround you in sound where as the JPW's it is more like the sound is in front of you.

Could I live with one pair more than the other? I think the Mission 700S would win out in sound and the real walnut veneer.

Both are fantastic speakers.

JPW AP1 Speakers

On loan from a friend while he is on holidays is a pair of JPW AP1 speakers. These speakers were rated as a best buy in Britain during the mid 80's due to their quality components and the low retail price.

From what I read the PW stood for "prison workers" in the fact that these were made by inmates. I don't know how true that story is.

The AP1 is a simple acoustic suspension featuring Seas/Vifa woofers and tweeters, air core inductors and what looks like a 1st order cross on the woofer and a second order cross over on the tweeter, there is a resistor to tame the Vifa D 19TD tweeter.

This pair had been re foamed in the past 5 years.

Pioneer HPM-60

I just picked up a pair of Pioneer's legendary HPM series speakers, the HPM-60.

In the golden days of vintage audio 1975-1979 (I think continued into the late 80's) the war for domination was lead by Pioneer. The king daddy no budget spared receiver of the day was the Pioneer SX-1280 and SX-1980 which competed with the Yamaha CR-3020, Sansui G-3300, Sony STR-V7 and another legend, the Marantz Model 2500. This was in the day of real "watts per channel" as in 200+ watts continuously, not peak power for micro bursts as receivers are marketed today.

It is fair to say that Pioneer and Marantz won the vintage war as today their receivers still command a big premium over their rivals, a true testament to their quality 35 years later. Here is an interesting article on why 30 year old receivers sound better than today's crap. And another interesting shootout between a Pioneer SX-1980, a Sony STR-V6 and a newer Yamaha RX-V1800.

Back to the Pioneer HPM Series speakers, 1n 1975 Pioneer scooped JBL's Vice President of Engineering, Bart Locanthi who developed JBL's most famous loudspeaker the JBL L100 Decade, remember these where the days when no expenses were spared to gain market share.

The Pioneer HPM-100 was a direct competitor to the JBL L100 with hints of the JBL 4311, the HPM-60 was designed to rival the JBL L36, the HPM-40 was targeting JBL's L26 and the HPM-30's was targeting the JBL L16.

Pioneer had to differentiate themselves from JBL so they added the "Super Tweeter" which was probably more of a marketing schtick than anything else. The Super Tweeter is a thin film foil over foam with to leads attached, no magnet just a current across the film. They do make noise but their output is very low, I bet the sales pitch was that it works but you just can't hear it.

The Pioneer HPM-60 have been playing for the past 24 hours and I can hear the JBL low end in these speakers, they sound like the JBL L26 in that sense but the mid range is there and the tweeter is not a harsh as the JBL tweeters.

I can understand why the HPM 100 and the HPM 60's still command JBL prices in the vintage market.

Update: I have been running these speakers all weekend and these are awesome monitors, very forward sound. Very much like JBL's.

Mission 700S update

I sourced a couple Vifa D 19 TD tweeters from a pair of Mission 70 speakers, They were installed and sound better than I thought. There is  a couple of resistors on the crossover which tames the shrillness of the Vifa tweeter. When I was listening to the Mission 70 speakers, they have a simple 2nd order cross on the tweeter and the woofer rolls of naturally, the shrillness was evident.

The Philips tweeters ended up in the Mission 70 which sound good.

Now these Mission 700S are 100% original and sound fantastic, no wonder I bought these as my first speaker ever.

Visonik David 4000

I just stumbled upon another mini speaker this time it is a pair of Visonik David 4000's. These little guys were made in Germany and were the predecessor of the Visonik David 5000.

The DAVID 4000, presented in 1978, was particularly innovative because its case was cast in aluminium. It resulted in new benchmarks for machining, resonance-behaviour and stability of the case. The DAVID 5001, nowadays still in production, endues over these exclusive technological features.

These guys will need to be re foamed as the foams are cracked, while I am at it these speakers have a 1st. order crossover to the tweeter with 6.8uf cap, so I might as well upgrade that as well.

Update: Unfortunately this project has come to an abrupt end as one of the tweeters died. I managed to re foam the woofer and re cap the crossover and upon testing it one tweeter died. Looks like I will part these out on Ebay.

Another Energy 22 option

A follow up to my post from Saturday here is another drop in replacement.

JBL 033 Tweeter: From JBL L40 or L110. Faceplate is 5 3/8" crossover was 1800hz. I believe these were made by Audax and found in Infinity speakers also.