[Photo] Gallstone hybrid power amplifier using switching power supply

The pre-amplifier uses a European-made TESLA brand low-noise high-cheek double transistor PCC88. The tube gain is moderate (μ = 33), the anode allows a large current (Ia = 15mA), the transconductance is high (12.5mA / V), and the required anode voltage is low. Use it to connect to SRPP mode to get a voltage gain of about 25 times.

In order to improve the sound quality, reduce interference and stabilize the working point, the following measures were taken for the power supply of PCC88 filament: 1. Buck power supply. The filament voltage is reduced from the standard 7V to 6.5V, which can greatly reduce the thermal noise of the tube and increase the stability of the circuit. 2. The filament power supply is obtained from the switching power supply through the LM317, and adopts a suspended structure to avoid the impact on the working state of the electronic tube and the sound quality, 3. Increase the filament potential, divide the anode voltage through two resistors, and raise the filament potential to 1/3 times of the positive pressure (the two resistors also serve as high-pressure discharge), reducing the filament and anode, especially with U2 The potential difference between the tube grid and the cathode can effectively reduce noise interference. 4. Use fixed grid bias. -48V power is reduced to -2.7V by a 56k resistor and RD2.7 stabilizing tube. It is isolated by a 220k resistor and connected to the grid. The cathode is directly grounded, eliminating the need for self-bias bias on the cathode resistance The frequency response and distortion index of the large electrolytic capacitors connected in parallel are reduced.

The current amplification stage adopts a three-stage emitter follower, which sets a sufficient current gain to reduce the burden on the anterior bile duct. Two pairs of D669 / B649 are used to form the Darlington tube structure, which can eliminate the saturation shaving phenomenon caused by signal overload. When the front-stage tube is close to saturation, the current gain will rapidly decrease, so that the water of the last-stage tube will not enter the saturation zone far, and the signal "soft landing" will be achieved to avoid harsh distortion. Negative feedback is completely eliminated, and push-pull circuits are used at all levels.

The last stage uses two pairs of Toshiba Hi-Fi pair tubes 2SC2564 / 2SAl094 for parallel output. The tube fT = 90MHz, is three times the characteristic frequency of the common 2SC3280 / 2SAl301, current 12A. Power 120W. For the promotion level, the Hitachi fever pair tube 25D669 / 2SB649 is used. The fT of the tube is up to 140MHz and the power dissipation is 20W. Using it with the 2SC2564 / 2SAl094 can output a very warm and sweet tone.

The final stage is designed as a high-bias class A and B output, the tube static current is set to 360mA, so that the power amplifier tube always works in the linear amplification area, and at the same time, it can also get a class A power (8Ω) of about 8W. Power up to 140W!

Use high-frequency switching power supply as the energy supply of the whole power amplifier (see Figure 2). The tube power supply uses the Sanyo 83P movement color TV switching power supply circuit, which is self-made with slight modifications. The rear stage power supply uses two Taiwan-made Mingwei brand industrial-grade S-320—48 switching power supplies to form a ± 48V, 6.5A power supply, with a power of 320W, a switching frequency of 167kHz, and overcurrent, overvoltage, and overheating. Protection function, built-in automatic air cooling system.

Follow the star-point one-point grounding rule on the circuit layout. Except that the static working point of the final transistor needs to be patiently and repeatedly debugged, the whole machine can get a beautiful and beautiful playback effect without too much adjustment.
Technical area detailed analysis of Doherty power amplifier design load traction principle (top) detailed analysis of Doherty power amplifier design how to improve efficiency (bottom) analysis of voltage follower input and output error analysis Solve the effect of power amplifier on emi

Follow WeChat

Interesting and informative information and technical dry goods

Download Audiophile APP

Create your own personal electronic circle

Follow the audiophile class

Lock the latest course activities and technical live broadcast
Collect People collection
share it:
comment
Publish

related suggestion

Avago introduces new high linear power amplifier module products

Avago Introduces New High Linear Power Amplifier Module Product Avago Technologies ...

Published on 2010-03-12 11:01 • 325 views
Avago introduces new high linear power amplifier module products
Using LM1875 and 2SA1943 / 2SC5200 ...

The circuit is shown in Figure 1. The chip IC uses the LM1875 of the American NS company, which has a soft tone and low distortion (0.015% ...

Posted at 2006-04-17 23:28 • 2226 views
Using LM1875 and 2SA1943 / 2SC5200 ...
Appreciate a variety of giant power amplifiers

The word "Monster" has both positive meaning and ...

Posted at 2006-04-17 23:27 • 1406 views
Appreciate a variety of giant power amplifiers
100W Digital Power Amplifier Made with Gate Driver IC

When the output power of the digital power amplifier is greater than 50W, it is impossible to use only ...

Published on 2006-04-17 23:27 • 995 views
100W Digital Power Amplifier Made with Gate Driver IC
Detailed explanation of class AB power amplifier

If an "audiophile" is a group of people who are never satisfied with the sound and "loved the new and the old" with the audio equipment. Then just rely on these so-called "fever spirits" ...

Published on 2006-04-17 23:27 • 6112 views
Detailed explanation of class AB power amplifier
Transistor 15W Class A power amplifier

First, the circuit principle and characteristics 1. Power amplifier part (see Figure 1)

Published on 2006-04-17 23:26 • 1261 views
Transistor 15W Class A power amplifier
"Simple first" transistor Class A audio power amplifier

There is a well-known saying in the Hi-Fi world that is "briefness first." This means that if ...

Published on 2006-04-17 23:26 • 4341 times read
"Simple first" transistor Class A audio power amplifier
Simple and practical TDA2822M integrated power amplifier

Simple and practical TDA2822M integrated power

Published on 2006-04-17 23:25 • 2750 views
Simple and practical TDA2822M integrated power amplifier
TDA2030 audio power amplifier

TDA2030 is ...

Published on 2006-04-17 23:22 • 1049 views
TDA2030 audio power amplifier
STK465 audio power amplifier

STK465 thick film ...

Published on 2006-04-17 23:22 • 4311 reading
STK465 audio power amplifier
Video Recorder RF Power Amplifier

This RF power amplifier can output 2-3 channel signals, covering an area of ​​about one square kilometer, is ...

Published on 2006-04-17 19:10 • 275 times read
Video Recorder RF Power Amplifier
[Photo] 15w RF power amplifier

Published on 2006-04-15 21:00 • 440 views
[Photo] 15w RF power amplifier
[Photo] Broadband high frequency power amplifier

Published on 2006-04-15 20:53 • 802 views
[Photo] Broadband high frequency power amplifier
Low frequency power amplifier

Low frequency power amplifier

Published on 2006-04-15 13:20 • 2354 times read
Low frequency power amplifier
[Photo] TDA2030 audio power amplifier

Published on 2006-04-15 13:10 • 1249 times read
[Photo] TDA2030 audio power amplifier
[Photo] Transistor 15W Class A Power Amplifier

Looking at the Hi-Fi amplifiers currently on the market, the output power is 100W ...

Published on 2006-04-15 13:10 • 1306 times read
[Photo] Transistor 15W Class A Power Amplifier
[Photo] 125W Class D Subwoofer Power Amplifier

With the newly launched LM4651 and LM465 from National Semiconductor ...

Posted at 2006-04-15 13:10 • 337 views
[Photo] 125W Class D Subwoofer Power Amplifier
[Photo] Mark Levinson No. 30 ...

Posted at 2006-04-15 13:05 • 1336 views
[Photo] Mark Levinson No. 30 ...
[Photo] 45W transistor tube hybrid power amplifier

EL34 (6CA7) was first launched by Philips in 1956 ...

Published on 2006-04-15 13:05 • 1443 views
[Photo] 45W transistor tube hybrid power amplifier
[Photo] 32W hybrid audio power amplifier

This article cleverly combines the electronic tube EL34 and the transistor (op amp), ...

Published on 2006-04-15 13:05 • 1312 views
[Photo] 32W hybrid audio power amplifier
[Photo] Simple fool power amplifier

"Simple" means the circuit of the amplifier is simple, making it easier, as long as the picture ...

Posted at 2006-04-15 13:04 • 2479 views
[Photo] Simple fool power amplifier
[Photo] LM386 low voltage audio power amplifier ...

1. Description: & nb ...

Posted at 2006-04-15 13:04 • 1397 times read
[Photo] LM386 low voltage audio power amplifier ...
[Photo] Class A power amplifier using SAP15N / P audio pair tube ...

The Class A transistor power amplifier has a warm and sweet tone, which makes people tempted. But the temperature rise of Class A amplifier ...

Published on 2006-04-15 13:03 • 3767 views
[Photo] Class A power amplifier using SAP15N / P audio pair tube ...
[Photo] Using TDA7294 and 2SA1216 / 2S ...

The circuit is shown in Figure 5, ...

Published on 2006-04-14 23:34 • 3043 times read
[Photo] Using TDA7294 and 2SA1216 / 2S ...
var check_allow = "/d/Api/iscantalk.html"; var add_url = '/ d / article / write /'; function CheckLogin () {now_uid = ''; var ElecfansApi_checklogin = '/ webapi / passport / checklogin'; var logout_url = "{: U ('Login / logout')}"; var logout_url = 'http://bbs.elecfans.com/member.php?mod=logging&action=logout&refer=front'; $ .get (ElecfansApi_checklogin, function (data, textStatus) {if (data! = "") {EchoLoginInfo (data); CheckEmailInfo (data); data = $ .parseJSON (data); now_uid = data.uid; / * var login_content = 'write an article
'+ data.username +'
Quit '; * / var login_content =' write an article
'+ data.username +'
Set exit '; $ (' # login_area '). Html (login_content); var win_width = $ (window) .width (); if (win_width> 1000) {$ ("# mine"). MouseDelay (200) .hover (function () {$ ("# mymenu"). show ();}, function () {$ ("# mymenu"). hide ();});}} else {var content = 'Login Registration'; $ ('# login_area'). html (content); $ (". special-login"). click (function (e) {$ .tActivityLogin (); return false;});}});} $ (function () {// comment ------------------------------- var comment = $ ("# comment"); var comment_input = $ ("# comContent"); // Submit comment click event interaction $ ("# comSubmit2"). on ('click', function () {var content = comment_input.text (); // Empty input box comment_input. html (""). focus (); // Submit data to server $ .ajax ({url: '/plus/arcComment.php', data: {aid: $ ("# webID"). val (), dopost : 'apiPubComment', content: content}, type: 'post', dataType: 'json', success: function (data) {// Data format returned: if (data.status == "successed") {// Build temporary comment DOM var dom = ''; dom + = '
'; dom + =' '; dom + ='
'; dom + ='

'+ data.data.username +' '; dom + ='

'; dom + =' '+ content +' '; dom + =' '; dom + =' just now '; dom + =' '; dom + =' '; // insert a temporary comment to the list $ ("# comment ") .append (dom);} if (data.status ==" failed ") {// alert (data.msg); layer.msg (data.msg);}}}); return false;}); (function () {/ * * Insert single sign-on JS * / var setHost = 'https://passport.elecfans.com'; // Set domain name var script = document.createElement ('script'); script.type = 'text / javascript'; script.src = setHost + '/public/pc/js/t.passport.js'; script.setAttribute ("id", "sso_script"); script.setAttribute ("data-ssoSite", setHost); script.setAttribute ("data-ssoReferer", encodeURIComponent (location.href)); script.setAttribute ("data-ssoSiteid", "11"); var body = document.getElementsByTagName ("body"). item ( 0); body.appendChild (script);}) () / * * It is recommended to modify the style of the article without a picture * * / $ (". Article .thumb"). Each (function () {if ($ (this). find ('img'). attr ('src') == "") {$ (this) .find ('img'). remove (); $ (this) .parent (). css ('padding-left ',' 0px ');}}); / * Baidu share * / window._bd_share_config = {common: {bdText: '', // Custom share content bdDesc: '', // Custom share summary bdUrl: window.location.href, // Custom share URL address bdPic: ''} , share: [{"bdSize": 60, "bdCustomStyle": true}]} with (document) 0 [(getElementsByTagName ('head') [0] || body) .appendChild (createElement ('script')). src = 'http://bdimg.share.baidu.com/static/api/js/share.js?cdnversion=' + ~ (-new Date () / 36e5)]; var add_url = '/ d / article / write / '; // var check_allow = "{: U (' Api / iscantalk ')}"; var check_allow = "/ d / api / iscantalk"; var click_items_length = $ ('. art_click_count '). length; if ( click_items_length> 0) {var id_str = ''; $ ('. art_click_count'). each (function () {id_str + = $ (this) .attr ('data-id') + ',';}) // var url = "{: U ('Api / getclickbyids')}"; var url = "/ d / api / getclickbyids"; var id_data = 'id_str =' + id_str; $ .ajax ({url: url, data: id_data, type: 'post', dataType: 'json', success: function (re) {if (re.list.length> = 1) {var list = re.list; for (var i in list) {var t emp_id = list [i] ['id']; var temp_span = $ (". art_click_count [data-id =" + temp_id + "]") temp_span.html (list [i] ['click']);}} }})} $ ("# comContent"). click (function () {if (now_uid == '') {$ .tActivityLogin (); return false;}}) $ (function () {var follow_wrap = $ ( ".author-collect"); var now_uid = "{$ _super ['uid']}"; var face_src = "{$ _super ['uface']}"; var getFollowNum = $ (". followNum strong"). html (); // Follow $ (window) .on ('click', '.author-collect', function () {if (now_uid == '') {$ .tActivityLogin (); return false;} if ( $ (this) .attr ('id') == 'follow') {$ .post ('/ d / user / follow', {tuid: article_user_id}, function (data) {// Data format returned: if (data.status == "successed") {$ (". followNum strong"). html (++ getFollowNum); follow_wrap.html ('followed'). attr ('id', 'cancelFollow'). css ( 'background', '# 999'); var follow_user = ' '; $ (' # follow_list '). append (follow_user);} if (data.status == "failed") {alert (data.msg);}});} else {// Unfollow if ($ ( this) .attr ('id') == 'cancelFollow') {$ .post ('/ d / user / cancelFollow', {tuid: article_user_id}, function (data) {// Data format returned: if (data .status == "successed") {follow_wrap.html ('Follow'). attr ('id', 'follow'). css ('background', '# f90'); $ (". followNum strong"). html (-getFollowNum); $ ('# follow_list .face'). each (function () {var target_uid = $ (this) .attr ('data-uid'); if (target_uid == now_uid) {$ ( this) .remove ();}})} if (data.status == "failed") {alert (data.msg);}}); return false;}}});});}); / * var myface = "{$ _super ['uid'] | avatar}"; var myname = "{$ _super ['username']}"; var article_id = {$ article ['id']}; var article_user_id = {$ article ['mid']}; // Article author ID $ (function () {<notempty name = "clearnum"> // Reduce the number of reminders var count = parseInt ($ ("# noticeCount"). html ()); count = count-{$ clearnum}; $ ("# noticeCount"). html (count); if ( count

The start-up battery is the soul of your vehicle.  It starts the Engine, and generates the energy necessary for the operation of all other vehicle's electric aspects. But did you know that it only has two years of life approximately?  Since during the unloading process and float charging, the battery's negative plate is sulphated fast, Reducing the functional capacity of the battery, until its complete inoperative. That's why we present the start-up Battery Pulse Protector. We offer you a fully automatic battery maintainer and protection system, it works 24 hours a day. Battery protector is not a battery charger. It is a patented electronic Sulfuric Crystal Cleaner which will eliminate the battery sulphation which is the main cause of problems and failures in lead acid start-up batteries. This battery pulse desulfator keeps the battery's condition as new, provides faster starts up your car or truck. Extends battery lifespan up to two or more times and reduce recharge time. Increase the capacity for your charge to last longer between recharges. Helps to protect the environments because it reduce the number of batteries that are discarded every year.

How is it installed? Lugs connect directly to the battery terminals.Easy Installation of 12V300Ah Battery Smart Pulse Protector

Designed especially for frequently-charged 12-Volt battery systems, the 12V Battery smart pulse protector and pulse maintainer ensures maximum performance on both single 12-Volt lead-acid batteries as well as two or three 12-Volt batteries connected in parallel. The battery pulse protector is ideal for any kind of vehicle or UPS with a 12-Volt battery system that is charged on a regular basis, including cars,trucks, ships, emergency vehicles,military battery backup power and vehicles in sudden war,wind and solar power battery, motor, UPS.Installation to Cars start up battery GPS and Bluetooth


Start-up Battery Protector

Start-up Battery Protector,Start-up Solar Battery Protector,Start Up Battery Regenerator,Car Battery Intelligent Protector

Shenzhen Daceen Technology Co., Ltd. , https://www.daceen-sz.com