Manufacturer : NPO "Okeanpribor", St. Petersburg.
Purpose and scope : for high-quality reproduction of music and speech programs in stationary living conditions. The recommended power of a high-quality household amplifier is 10 - 100 W. The preferred installation option is on a stand 0.3 - 0.5 m. 150AC-001 “Corvette” is identical to 75AC-001 “Corvette” .
Design features of 150AC-001 “Corvette”
A distinctive feature of the system is that it has a high level of characteristic sensitivity and the ability to withstand high electrical power values, which allows you to reproduce programs with an extended dynamic range without noticeable distortion. This makes it possible to use the 150AC-001 not only with conventional, “analog” program sources, but also with a digital laser player.
The speaker body is made in the form of a rectangular non-collapsible box made of chipboard veneered with valuable wood veneer. The thickness of the case walls is 16 mm, the front panel is three-layer (plywood - chipboard - plywood) - 24 mm. The design of the housing includes elements that increase the rigidity of the housing and reduce the amplitude of vibrations of the walls - stiffeners and couplers.
The 150AC-001 uses a set of heads designed for a new generation of high-quality high-sensitivity speakers manufactured by , which is located in the city of Krasny Luch. The design of head assemblies using specially developed software packages for calculating their characteristics on a computer made it possible to create effective heads with low nonlinear distortions. The heads are framed with decorative overlays made of ABS-2020 plastic: the woofer head overlay is round, with six mounting holes, the midrange and treble head overlay is rectangular with eight mounting holes. The midrange head is isolated from the inside of the total volume of the housing by a special sealed pipe connecting the front and rear walls of the housing. Pipe length 290 mm, diameter 110 mm, volume 3 liters. The heads are located on the front panel symmetrically relative to the vertical axis. At the same time, in order to reduce the unevenness of the frequency response of sound pressure in the frequency range of 1000 Hz, which occurs due to reflection from the front panel of the speakers, the midrange head is installed closer to the upper edge of the front panel, above the high frequency head.
On the front panel, in addition, there is a decorative nameplate with the name of the speaker, the shape of the typical frequency response of sound pressure and overload indicators for the low-frequency, mid-range and high-frequency bands of the speaker; a hole with a diameter of 75 mm, which is the output hole of a bass reflex pipe 91 mm long. The geometric dimensions of the bass reflex ensure tuning to a frequency of 36 Hz.
The internal net volume of the speaker is about 70 liters. To reduce the influence of resonances of the internal volume on the frequency response of sound pressure and the sound quality of speakers, the speaker housing is filled with effective sound-absorbing material ATM-1.
Electric filters are mounted inside the housing, designed using optimal synthesis methods using a computer and providing, in addition to electrical separation of low-, mid- and high-frequency speaker bands, also correction of amplitude and phase characteristics.
Filters provide band separation: between the bass and midrange heads - 600 Hz; filter on the side of the bass head – 2 orders, and on the side of the midrange head – 3 orders; between the mid and high frequency heads – 6000 Hz; the filter on the side of the midrange head is 3 orders, and on the side of the high frequency head – 4 orders. The design of the filters uses resistors of the C5-35V type, capacitors of the MBGO type, and an inductor on plastic frames with “air” cores.
The acoustic system 150 AC-001 has a circuit for protecting loudspeaker heads from electrical overloads and indicating the presence of such overloads in the input signal. When a signal appears at the speaker input that exceeds the permissible power for any speaker, the protection device reduces the signal to a safe value for each corresponding head. The occurrence of an overload in any band of the speaker is warned by the glow of indicators on the front panel above the corresponding inscription - LF, MF or HF.
The protection and indication circuits are configured to operate when a real musical signal with a peak power of 75–100 W is applied to the speakers, which corresponds to a sound pressure level of at least 110 dB. When the PROTECTION plug is installed, the circuit is triggered at signal peaks of 300 - 350 W, which corresponds to a sound pressure level of about 116 dB. The first mode provides maximum reliability; the second is the maximum dynamic range and is used when testing for maximum short-term power.
On the base of the speaker there are four plastic legs, and on the rear wall there are terminals for connecting supply wires and a PROTECTION socket for installing a contactor plug that changes (increases) the protection threshold.
Operating manual on disk (sent by Kirill).
General information about the amplifier
"Corvette 100U-068S" is a complete amplifier of Soviet production. It was created on the basis of the legendary "Brig", but with the use of some modifications. The result was a unique (for that time) device with high power density and good appearance. However, it was pleasing to the eye only in its new condition. A year later, his appearance became, to put it mildly, unpresentable. Currently, it is impossible to find a non-worn Corvette at a flea market. At one time, this amplifier belonged to the category of the highest complexity. This means that in theory it should have provided incredibly high-quality sound. Many vintage lovers still believe this. However, the Corvette 100U-068S amplifier cannot be compared with the same Brig. Even though it was made in his image and likeness. However, enough of the lyrics. It's time to move on to the dry and boring language of numbers. But first, let's look at the design and appearance of the top Soviet amplifier.
Positive feedback from owners
So, what can those who managed to purchase a live Corvette 100U-068S say? The vast majority of owners are satisfied with their purchase. Even though the “Corvette 100U-068S” amplifier circuit is designed rather clumsily. When used gently at home, this amplifier produces very high-quality sound and brings incredible joy to its owners. Some music lovers note that the best results are obtained when using it with Amphiton 50AC speakers, an external computer sound card (or a high-quality CD player) and music in some lossless format (FLAC, APE, WV, ALAC, etc.) . Well, it's quite possible. Happy owners of this device claim that there is no need to modify anything in the amplifier, as this will “kill the soulful analog sound.” Let's take these enthusiasts at their word.
Sound quality
The most interesting thing is the sound quality of this device. According to the passport, this amplifier should provide excellent sound quality. But is it really so? Let's start with the fact that the sound of this device is slightly worse than that of the same "Brig". Although the scheme used is almost the same. It's all about improvements and upgrades to an already good scheme. What problems does the Corvette 100U-068S amplifier have? The electrical circuit is clumsily soldered. Hence the main problem. A simple wire winding is also used, which also degrades the sound. The power transformer is not made well enough, which leads to background noise. That is why this amplifier sounds noticeably worse than the Brig. But after appropriate modifications, it should sound as expected. But not everyone has the experience to carry out such manipulations. And what kind of Hi-End device is this, which after purchase you need to tinker with a soldering iron in your hands? But even without modification, the sound is very high quality (if you don’t compare it with the Brig). Therefore, you shouldn’t focus too much on this point.
Main technical characteristics of the amplifier
“Amplifier Corvette 100U-068S”, the characteristics of which we will now analyze, belongs to devices of a high degree of complexity. This means that its characteristics are advanced. And indeed it is. The range of reproduced frequencies starts at 10 hertz and ends at 70,000. This is the first sign of a Hi-End device. Now about the power. The nominal continuous power of the device with a speaker impedance of 6 ohms is 125 watts. That's a lot. Enough for a small concert hall. The rated short-term (peak) power with the same resistance is 150 Watts. Excellent results. Especially when you consider that these are “honest Watts” and not modern Chinese ones. Power consumption is 275 W. And this is at maximum amplifier load. In idle mode, it consumes only 30 watts. This miracle weighs almost 10 kilograms. Its dimensions are also not modest. But this is normal for devices that provide high-quality sound. Now let’s look at other features of the Corvette 100U-068S amplifier.
Negative reviews from owners
Those who leave negative reviews about this amplifier will not agree with previous comrades. These citizens claim that the weakest point of the device is resistors and capacitors. They say they burn so much that you only have time to change them. True, they immediately declare that they used acoustics with a power of 200 watts together with the Corvette 100U-068S amplifier. The operating instructions, of course, have long been lost, but we can safely say that this amplifier physically cannot support such a powerful speaker system. That's why it burns. The design of the device also received negative reviews. And it’s hard to argue here. Indeed, all used Corvettes look worse than Chinese consumer goods. But, alas, nothing can be done about this.
Choosing acoustics for this amplifier
Not every speaker system is suitable for the Corvette 100U-068S amplifier. You need speakers so that the amplifier can drive them. It works well with loudspeakers such as Radiotekhnika S-90. They have suitable resistance and not particularly high power. Just what you need for this amplifier. Amphiton 50AC will also perform well. They can produce clear and balanced sound. Just what the sophisticated listener needs. There is no point in considering older speakers, since very few have survived to this day in decent form. Also, you should not take into account the speaker systems released in Russia after perestroika. At that time, we somehow forgot how to make high-quality acoustics. Now let's look at the reviews from the happy owners of this amplifier.
