Sunday, October 24, 2010

Review: Adcom GFA-535 amplifier



The Adcom GFA-535 is the little brother to the famed 545 and 555 amplifiers. It features true dual mono construction with each channel getting its own power transformer and power supply capacitors. With a simple design by the famed Nelson Pass, it features pretty much the same input/driver circuit as the big amplifiers and also has bi-polar output transistors. Rated at a conservative 60WPC, the original version has two sets of speaker output using twist connectors for bare wires. The small size makes it perfect for sitting on top or underneath a matching Adcom preamplifier.

For $125USD, I soon found an early version in my hands. It worked perfectly out of the box too. Adcom stuff seems to hold up fairly well and this has been a joy compared to some of my older pieces of gear.


Sonically, it drives my KEF Q60 speakers without any trouble at all. Bass is solid and only a faint touch of solid-state glare exists that smooths out with continued use. Oddly enough, the much more vintage Dynaco ST-80 sounds more colorful and tubey - perhaps it is the aged carbon composition resistors and electrolytic output coupling capacitors. The 535 having a much more leaner/modern sound. The Adcom also has more power in reserve and can handle more complex loads. So pick your poison and run with it. I can live with either amplifier for low powered solid-state, but the 535 wins out for its matching aesthetics with the GTP-400 preamplifier.


Second System:
Adcom GTP-400 tuner preamplifier
Dynaco ST-80 refurbished
Dual CS-5000 turntable with AT95E cartridge
Pioneer DVD-V7400 DVD player
KEF Q60 speakers
various budget cables


.

Wednesday, October 20, 2010

Review: Adcom GTP-400 tuner preamplifier


Owning vintage gear from the hey-day of the 60s and 70s can be troublesome since switches, pots and electronic components can go bad. Replacing aged capacitors and resistors is an easy task, but finding the right fitting switch can be difficult. For that reason, basic amplifiers seem to age better than preamplifiers which can be noisy. With that in mind, I decided to replace my Dynaco PAT-4 preamplifier & AF-6 tuner combination with something a little more modern for family use.

Adcom has been around since the 1970s, starting as company that made phono cartridges. By the time the 80s rolled around, they were one of the go-to companies for budget solid-state gear. Several of their components made Stereophile's Recommended Component list and even to this day, my father runs the classic GFP-555 preamplifer and GFA-555 amplifier. During the early 90s, I owned the highly regarded GFP-565 which did not work out for me due to overall system imbalances - it just didn't sound right with my then Snell JIII speakers and a Harman-Kardon Citation V tube amplifier.

After much thought, I decided on purchasing an Adcom GTP-400 for a paltry $125. The GTP-400 is a basic preamplifier that also includes an AM/FM tuner and tone controls are included along with a MM phono preamplifier. The number of switches and knobs makes for a busy looking unit, but the simple black case and blue tuner LED lettering give it a conservative look. There is nothing flashy going on here, just stolid engineering.


Removing the Dynaco preamplifier and tuner was easy enough to do and I soon had the GTP-400 hooked up to sources and a Dynaco ST-80 amplifier. Now there is a strange pair! I have an Adcom GFA-535 coming soon and will report on that in due time.

At least on this low resolution system, sound differences between the Adcom and Dynaco are fairly minor. The strong character of the Dual CS-5000 & AT95E combination still shines through in all its analog glory, while the line section is smooth. I would never mistake the GTP-400 for a tube preamplifier since there isn't tons of depth or dimensionality to the sound. But dynamics and bass control are excellent, plus there is no hiss or hum to worry about. This is trouble free audio at a budget and is highly recommended for those looking to get into this crazy hobby.

A quick word on the tuner section - I'm no fan of digital tuners since they can skip over weaker signals. In comparison, an analog tuner can be fine-tuned with fine gradual turns of the knob. I would think of the GTP-400 as a preamplifier with the side-benefit of having a decent tuner - perfect for background music while cleaning or reading books.


Second System:
Dynaco PAT-4 modified
Dynaco AF-6 tuner
Dynaco ST-80 refurbished
Dual CS-5000 turntable with AT95E cartridge
Pioneer DVD-V7400 DVD player
KEF Q60 speakers
various budget cables


.

Monday, October 18, 2010

Review: Dual CS5000 turntable


On my second system, I've been less than happy with my Panasonic linear tracking turntable. The sound, with a budget p-mount cartridge, has been tiny and prone to inner groove distortion. Since I spin tons of vinyl, I've decided to replace it with something better. Since this was going to be a turntable for family use, I wanted something that would lift the tonearm at the end of the record. Some searching online brought me to a used $395 Dual CS-5000 turntable.

The CS5000 was a popular 80s semi-automatic European turntable that came from the long line of 505 tables. It features a microprocesser controlled, quart referenced DC motor that drives the platter with the use of a belt. The tonearm is low mass and has a removable headshell and adjustable VTA. The CS5000 is also a suspended design, isolating the motor, arm and platter from the plinth. I found that construction quality is very good and the overall look with the oak plinth and smokey dustcover is very classy. The platter is a little on the lightweight side, but the mat is extremely thick and dense.


Upon receiving the Dual, I had to buy a cartridge. Since this is a budget rig, an Audio-Technica AT95E was selected for its reported smooth sound. Installation with the removable headshell was a snap and I soon had the turntable up and running. Using the CS5000 is easy - turn it on and push the arm until the needle rests over the record. The platter spins up to speed and 2-3 seconds later, the needle drops onto the records. When playing is done, the arm lifts but does not automatically return. Hence the term "semi-automatic".

Even through my vintage solid-state Dynaco gear, the overall sound is extremely rich and involving. Compared to my old Panasonic table, the CS5000 is more dynamic and boasts deeper bass too. Inner groove distortion is now so minimized that I have a hard time knowing that the end of the record is coming. The Dual also has a pure analog sound that is oh so enjoyable. Though lacking the detail of my VPI turntable, the Dual still has a rightness that digital seems to have a hard time matching. Vinyl noise is kept to a minimum and even normally hard to play records have an extremely clean presentation. There is a bit of a golden honey-tone to the sound that reminds me of good vacuum tube systems. Perhaps things could get a little thick with the wrong amplification chain, but it sounded just right with my current setup.

I don't know if it is the DC motor or faulty memory, but the Dual seems to have a less "washy" sound than my old Rega P2 (that I foolishly sold). The arm on the CS5000 is a little chintzy but works. I can't really comment on soundstaging, depth or the lowest/highest frequencies since this system really isn't about that.

The Dual CS-5000 is highly recommended for a budget or even a mid-priced system. This is an excellent way for someone just starting to get into vinyl.


Second System:
Dynaco PAT-4 modified
Dynaco AF-6 tuner
Dynaco ST-80 refurbished
Panasonic linear tracking turntable
Pioneer DVD-V7400 DVD player
KEF Q60 speakers
various budget cables

.